A combination junction block and fuse panel is mounted on the dash under the instrument panel. (See Fig. 13-1) It is color coded to correspond to the wiring color code. Each unit supplied from the fuse panel is also color coded to simplify servicing. The cigar lighter fuse is located on the back of the lighter body. The instrument panel lights are fused on the side of the headlamp switch. The 1957 instrument cluster has a printed circuit. All units in the cluster are connected by a multiple contact plug, which is keyed to prevent improper assembly. (See Fig. 13-2)

The printed circuits will not be visible as they are shown in the illustration. They are illustrated here merely to show the relationship between the units and the connecting plug. There is no service other than replacement of the circuit panel.

Body wiring is likewise connected to chassis wiring by a multiple contact plug which is located under the left side of the instrument panel.

1957 Oldsmobile Fuse Panel


1957 Oldsmobile Wiring Diagram


1957 Oldsmobile Instrument Cluster and Plug



The charging circuit consists of the battery, generator, regulator, and generator warning light. The simplified wiring diagram shown in Fig. 13-4 illustrates this circuit.

1957 Oldsmobile Charging Circuit



The Delco battery used in all 1957 models is a 12 volt, 70 ampere-hour unit containing 11 plates per cell. It is assembled in a hard rubber container, has rubber separators, and is fitted with the “visual level fill” cell covers.





The standard generator is a 12 volt, 30 ampere, brush shunt unit. Cars equipped with air conditioning will have a 12 volt 35 ampere generator. The output of the generator is limited by the generator regulator. The brushes are not manually adjustable. They are held by reaction type holders pro­ vided with springs which cause them to bear on the generator commutator. Generator structure and nomenclature are shown in Fig. 13-5.

1957 Oldsmobile Generator Details



The regulator is a 3 unit Delco-Remy 12 volt unit containing a cutout relay, voltage regulator, and current regulator. (See Fig. 13-6) It is designed for use with a Delco-Remy shunt type generator in a system with a negative ground.

1957 Oldsmobile Regulator

Cutout Relay – The cutout relay closes and opens the charging circuit between the generator and the battery. When the generator voltage reaches the value for which the cutout relay is adjusted, the contact points close, allowing the current to flow toward the battery. When the generator voltage falls below that of the battery, the points open to prevent the battery from discharging through the generator when the engine is idling or stopped.

Voltage Regulator – The voltage regulator limits the voltage of the electrical system to a safe maximum. The contacts of the voltage regulator oscillate at a high rate of speed, opening and closing the points. This action intermittently introduces resistance into the generator field circuit, thereby reducing voltage.

Current Regulator – The current regulator prevents overheating of the generator armature by limiting generator output. When generator output reaches the value for which the current regulator is set, the points open, inserting a resistance into the generator field circuit. This causes the generator output and field voltage to decrease, allowing the contact points to close. This cycle occurs many times each second, thereby limiting generator output to a safe maximum.



The red generator warning light, located in the instrument panel, should light when the ignition key is turned on. If the light does not operate with the ignition switch on and the engine stopped, either the bulb is burned out, the generator has an open circuit, or the instrument lamp fuse is blown.

When generator voltage output becomes greater than the battery voltage, the red light should go out. This does not, however, indicate whether the battery is being charged or the regulator is functioning properly. This should be checked with an A.V.R. unit.




  1. Check battery liquid level every 2, 000 miles or once a month (more often in hot weather). Level should reach the bottom of the vent well.


  1. Clean top of battery and terminals every 4,000 miles and check tightness of battery hold-down bolts. To properly clean battery:
    a. Make sure vent plugs are closed tight.
    b. Brush batter y with a diluted ammonia or soda solution. When the solution stops foaming, rinse with clear water.
  2. Check for pin holes or openings in the top of the battery. Seal them with a hot iron.
  3. Clean battery cable clamps with diluted ammonia or soda and rinse with clear water. Apply a thin coating of petrolatum to terminals and clamps before installing clamps.



  1. Fill hinged cap oilers at each lubrication period. If oiler on commutator end appears to be dry, fill it three times, allowing time for oil to saturate wick between fillings. The oiler on the drive end should never be filled more than once.
  2. Inspect the commutator and brushes for wear and cleanness (observe through end frame). If commutator is dirty, clean with number 00 sand paper, brush seating stone, or seating paste while engine is running. DO NOT USE EMERY CLOTH.
  3. If brushes are worn to less than haIf their original length, replace them as outlined under SERVICING OF UNITS IN THE CHARGING CIRCUIT.
  4. Check generator belt tightness and adjust if necessary.
    a. Place belt tension tool 33-70 on generator belt.
    b. Loosen generator adjusting link bolt.
    c. Tighten generator belt until the line on the gauge is even with the pointers as shown in Fig. 13-7.
    d. Tighten generator adjusting link bolt.

    1957 Oldsmobile Checking Belt Tension (2)




To check for excessive voltage drops caused by loose connections, burned or broken wires or other high resistances, proceed as follows:

  1. Ground the “F” terminal of the regulator.
  2. Connect an ammeter in series between the positive battery cable and the “BAT” terminal of the regulator. (See Fig. 13-8)

    1957 Oldsmobile Charging Circuit Test

  3. Turn off all accessories and operate the generator at a speed sufficient to produce a charging rate of 20 amperes.
  4. Measure the voltage drops at V 1, V 2, and V3 as shown in Fig. 13-8. V1 plus V2 should not exceed 0.5 volt. V3 should not exceed 0.3 volt. Excessive readings indicate high resistance in the areas checked.
  5. Remove the ground jumper from the “F” terminal of the generator and turn on all lights and accessories. Measure the voltage drop V4 as shown in Fig. 13-8. If this reading is mor e than 0.1 volt, excessive resistance is indicated in this portion of the circuit.
  6. If excessive resistance is indicated in any part of the circuit, clean and tighten all connections and check the wires and replace as necessary.



A hydrometer test will indicate the state of charge of a battery unless water has recently been added to the battery or it has been recently fast charged. A good hydrometer reading does not necessarily indicate that the battery will perform its normal functions. (See LOAD TEST)

Specific gravity of the electrolyte varies.004 units for every 10° difference between the temperature of the electrolyte and 80°F. The hydrometer reading must be corrected to 80°F.


a. Hydrometer gravity reading       1.235
Electrolyte temperature 110 F
Correction (4×3)                               +.012
Corrected gravity reading               1.247

b. Hydrometer gravity reading      1.250
Electrolyte temperature 0°F
Correction (4×8)                               -.032
Corrected gravity reading              1.218

A battery with a corrected specific gravity reading 1.215 is haIf charged.

If the corrected specific gravity of the electrolyte is less than 1.215 or varies more than.025 between cells, the battery should be removed for a slow charge and load test.



The cover of the regulator must be in position and the regulator must be at operating temperature. Operating temperature should be reached after about 15 minutes of regulator operation. The electrical checks should be made in the following order:


Voltage Regulator Setting

  1. Connect a 1/4 ohm fixed resistor (approximately 25 watts) into the charging circuit at the “BAT” terminal df the regulator. (See Fig. 13-9)

    1957 Oldsmobile Checking Voltage Setting

  2. Connect a voltmeter from the regulator “BAT” terminal to ground.
  3. Run engine at 1,600 R.P.M. for at least 15 minutes with cover in place to bring the regulator to operating temperature.
  4. Cycle the generator by either of the following methods:

Method A – Stop the engine; restart, and bring engine back to 1,600 R.P.M. and record the voltage setting.

Method B – Connect a variable resistor into the field circuit as in Fig. 13-9. Move the voltmeter lead from “BAT” to “GEN” terminal of regulator. With the generator operating at 1,600 R.P.M., slowly increase (turn in) the resistance of the variable resistor until genera­ tor voltage is reduced below 4 volts. Move voltmeter lead back to “BAT” terminal of regulator. Decrease (turn out) all of the resistance of the variable resistor. Record voltage setting.

  1. Check the temperature of the regulator and adjust the voltage according to the chart shown in Fig. 13-10.

    1957 Oldsmobile Voltage Correction Factors

  2. To adjust the voltage setting, remove the regulator cover and turn the adjusting screw. (See Fig. 13-11) Increase spring tension to raise the setting; decrease spring tension to lower the setting. Before taking the reading after each adjustment, replace the regulator cover as quickly as possible and cycle the generator. (The engine should be stopped while removing and replacing the regulator cover to reduce the possibility of causing a short.)

    1957 Oldsmobile Adjusting Voltage Setting

CAUTION: Final adjustment should always be made by increasing spring tension to assure contact between the screw head and spring support. Sometimes the spring support does not follow the screw head as spring tension is decreased, and it will be necessary to bend the spring support up to insure contact between the spring support and screw head before final adjustment is completed.


Cutout Relay Closing Voltage

  1. Connect a voltmeter between the regulator “GEN” terminal and ground. (See Fig. 13-12)

    1957 Oldsmobile Checking Closing Voltage of Cutout Relay

  2. Check cutout relay closing voltage by slowly increasing generator speed and noting the voltage at which the relay closes. Make sure relay opens when generator speed is decreased.
  3. Adjust the closing voltage to 12.8 volts by turning the adjusting screw clockwise to in­ crease the setting or counter-clockwise to decrease the setting. (See Fig. 13-13).

    1957 Oldsmobile Adjusting Closing Voltage on Cutout Relay


Current Regulator Setting

  1. Connect an ammeter into the circuit as shown in Fig. 13-14.
  2. Turn. on all lights and accessories and intro­ duce enough resistance across the battery to reduce the system voltage to 12.5 to 13 volts.
  3. Operate the generator at an engine speed of 1,600 R.P.M. for at least 15 minutes to establish operating temperature. The regulator cover must be in place.
  4. Cycle generator (See VOLTAGE REGULATOR SETTING) and note current regulator setting.
  5. Adjust current regulator to 30 amps (35 amps on air conditioned cars) in the same manner as that used for adjusting voltage regulator settings.

    1957 Oldsmobile Checking Current Regulator Setting


Check For Oxidized Regulator Points

  1. Turn on the headlights.
  2. Operate the generator at speed which will produce a charge rate of 5 amperes.
  3. Ground the “F” terminal of the regulator.
  4. If generator output increases more than 2 amperes, oxidized regulator contact points are indicated and the regulator should be re­ moved from the car and the contact points should be cleaned as outlined under SERVIC­ ING OF UNITS IN THE CHARGING CIRCUIT.





Batteries removed from the car for charging should be charged continuously at a low rate. Batteries may be safely slow-charged at a rate in amperes equal to 7% of the battery’s ampere-hour capacity. Ex: 7% of 70 A.H. = 4.9 amperes. This is called the “Normal” charge rate. The battery is fully charged when specific gravity readings taken at hourly intervals show no increase during three consecutive readings. Although the slow­ charge method is recommended for charging all batteries, discharged batteries in otherwise good condition, may be given a “boost” with a fast charger if time does not permit complete slow­ charging. When using a quick charger, it must be remembered that the battery is only receiving a partial charge and that the battery electrolyte temperature must not be allowed to exceed 120°F. If the battery heats excessively, quick charging must be discontinued.

Batteries removed from the car for further checking in order to determine whether or not the unit should be replaced, first should be brought to a fully-charged condition by slow-charging. Badly sulfated batteries may require a continuous slow­ charge for 48 hours or more before a rise in gravity reading occurs. If the specific gravity reading of any cell fails to reach 1.215 (corrected to 80°F.) or if there is a variation of more than 25 points between cells after thorough slow-charging, replace the battery. If the specific gravity of each cell is 1.215 or more and variation between cells is less than 25 points, the battery may be given a load test as follows to determine its ability to deliver current under load.


Load Test

CAUTION: Do not make this test if the specific gravity is below 1.215.

  1. Connect the battery-starter tester to the battery positive and negative terminals.
  2. Adjust the resistance knob to obtain 140 amps on the ammeter.

Voltmeter should read a minimum of 9.0 volts after 5 seconds. If the volt-meter reads less than 9.0 volts, it indicates that the battery does not have sufficient capacity and it should be further checked as follows:

  1. Slow charge the battery at rate of 1 amp per plate (11 plates x 1 = 11 amps) for 12 hours.
  2. Place 140 amp load across the battery.
  3. Quickly measure the individual cell voltages by piercing the sealing material over the cell straps.
  4. If the cell voltage falls below 1.5 volts or there is a difference of more than.2 volt between cells, the battery is not in satisfactory condition.

In order to determine the battery’s actual condition, it should be recharged slowly. If the slow-charge shows:

a. Little or no voltage increase in some cells – indicates these cells are shorted and battery should be replaced.
b. Uniform voltage increase in cells but un­ equal specific gravity at full charge – indicates loss of acid, and the acid should be readjusted and the battery again load tested.

CAUTION: The acid content of the battery should be adjusted only by a skilled battery technican.

c. Slow and uneven increase in both specific gravity and voltage indicates excessive sulfation. Continue slow-charge for 24 to 48 hours.




To disassemble the generator, remove the two through bolts and slide off the commutator end frame. The field frame (with brush rigging) can be further disassembled if necessary.


Cleaning and Inspection

  1. Check brush holders for bends or deformities which might prevent proper functioning. Check brush spring tension (28 ounces) as shown in Fig. 13-15.

    1957 Oldsmobile Checking Brush Tension

  2. Wash all metal parts except armature and fields in cleaning solvent. Degreasing sol­ vents will damage the insulation in fields and armature.
  3. Inspect generator ball bearing for roughness, scored races, and deformed balls.
  4. Check fit of armature shaft in commutator and frame bushing. Excessively worn bushings should be replaced.
  5. Inspect armature commutator for roughness. Rough commutators should be turned down and undercut. Check solder connections where armature wires connect to commutator riser bars.
  6. Place armature on growler and check for shorts by rotating armature with hack saw blade over core. (See Fig. 13-16) If saw blade vibrates, armature is shorted. If cleaning between commutator bars does not correct the vibration, replace the armature.

    1957 Oldsmobile Growler Test

  7. Place one lead of a 110 volt test lamp on the armature core and the other lead on each commutator bar. (See Fig 13-17) If lamp lights, armature is grounded and must be replaced.

    1957 Oldsmobile Checking Armature For Ground

  8. Place one lead of the 110 volt test lamp on field terminal and the other lead on the armature terminal. (See Fig. 13-18) If lamp does not light, check for loose connections. If no loose connections are found, field coils are open. Replace coils.

    1957 Oldsmobile Checking Field Coils For Open

  9. Ground one lead of test lamp on frame and place other lead on field terminal. (Be sure free end of field wire is not touching frame and field terminal insulation is not broken.) (See Fig. 13-19) If lamp lights, field coils are grounded. If ground in coils cannot be located and repaired, replace coils.

    1957 Oldsmobile Checking Field Coils for Ground

  10. Place one lead of test lamp on generator positive (output) lead and the other lead on generator frame. Make sure loose end of terminal lead is not touching frame.(See Fig. 13-20) If lamp lights, positive terminal insulation through frame is defective and must be replaced.

    1957 Oldsmobile Checking Positive Terminal Insulation

  11. Place one lead of test lamp on the positive (insulated) brush holder and the other lead on frame. (See Fig. 13-21) If lamp lights, brush holder is ground ed due to defective insulation at the frame.

    1957 Oldsmobile Checking Brush Holder

  12. Check armature for an open circuit by making a bar-to-bar check on the commutator.


Generator Repair

Loose Electrical Connections – When an open soldered connection is found during inspection, it may be resoldered provided rosin flux is used for soldering.


Turning Commutator – When inspection shows commutator roughness, it should be cleaned as follows:

  1. Turn down commutator in a lathe until it is thoroughly cleaned.

CAUTION: Do not cut beyond section previously turned.

  1. Undercut insulation between commutator bars 1/ 32″. This undercut must be the full width of insulation and flat at the bottom; a triangular groove will not be satisfactory. After under­ cutting, the slots should be cleaned out care­ fully to remove any dirt and copper dust.
  2. Sand the commutator lightly with No. 00 sand­ paper to remove any slight burrs left from undercutting.
  3. Recheck armature on growler for short circuits.


Installation of Generator

  1. After the generator has been assembled, position the generator on the engine and install the generator attaching bolts, but do not tighten.
  2. Install generator and fan belt.
  3. Using Tool J-4170 and a torque wrench (Tool J-1264), adjust belt torque tension to 16ft. lbs., and tighten generator adjusting link bolt. Tool 33-70 may also be used to check and adjust the belt tension.
  4. Torque generator adjusting bolts 14 to 17 ft. lbs.
  5. Connect positive generator lead and field lead to terminals on generator frame.

IMPORTANT: On radio equipped cars, connect the radio by-pass condenser to generator output (A) terminal.

  1. Polarize the generator by momentarily connecting a jumper wire between the “BAT” and “GEN” terminals on regulator.
  2. Start engine. If brushes squeak, seat them by placing brush seating paste on the commutator. The soft abrasive material of the paste will be carried under the brushes and wear the brush faces to the commutator contour in a few seconds.


Although electrical adjustments are made with the regulator on the car as outlined under CHECKS AND ADJUSTMENTS ON THE CAR, it is necessary to remove the regulator for cleaning contact points and adjusting air gaps on the three regulator units.



To remove the regulator, disconnect the leads from the regulator and remove the regulator to dash mounting screws.


Regulator Inspection and Adjustment (Removed from Car)

Contact Points

Inspect contact points for pits and oxidation. Replace points if badly burned. To clean the con­ tact points, loosen the upper contact bracket mounting screws and tilt the bracket as shown in Fig. 13-22. Check to make sure that the connector strap between the voltage and current regulators is insulated from the contact mounting screws on both the voltage and current regulators.

1957 Oldsmobile Cleaning Contact Points

The large flat contact point, located on the volt­ age regulator armature and the upper contact support on the current regulator, always develops a slight cavity and should be cleaned of oxides by using a riffler file.


If it is necessary to replace the upper contact points of the regulator, reassemble the regulator as shown in Fig. 13-23.

1957 Oldsmobile Contact Support Brackets


Cutout Relay Inspection and

Gap Adjustment

  1. Place fingers on armature directly above core and move armature down until points just close. Measure air gap between armature and center of core (020″). Check to see that points close simultaneously. To adjust air gap, loosen two screws at back of relay and raise or lower armature as required. (See Fig. 13-24).

    1957 Oldsmobile Adjusting Cutout Relay Air Gap

  2. Check point opening and adjust to.020″ by bending upper armature stop. (See Fig. 13-25).

    1957 Oldsmobile Adjusting Cutout Relay Point Opening


Voltage Regulator Inspection and Gap Adjustment

Push armature down to core and release it until contact points just touch and then measure air gap between armature and center of core. Air gap should be.075″. Adjust gap by loosening contact mounting screws and raising or lowering contact brackets as required. (See Fig. 13-26) Check to see that points are lined up and tighten screws after adjustment.

1957 Oldsmobile Adjusting Voltage Regulator Air Gap


Current Regulator Inspection and Gap Adjustment

Check and adjust current regulator air gap in exactly the same manner as voltage regulator. Air gap should be .075″.


Installation of Regulator

  1. With rubber gasket in place on regulator base and cover installed, install regulator and tighten mounting screws.

CAUTION: Do not tighten the mounting screws excessively as this will destroy the cushioning effect of rubber grommets in the mounting.

  1. Attach “BAT”, “GEN”, and “FIELD” leads to regulator and polarize generator by momentarily connecting a jumper wire to the “BAT” and “GEN” terminals on the regulator before starting the engine.
  2. Check and adjust the electrical settings of the regulator on the car as outlined und er CHECKS AND ADJUSTMENTS ON THE CAR



The new Delco-Remy Starting Motor is a 12- volt extruded frame type unit. It has four poles and a compound field – three field coils connected in series from the field terminal to the insulated brushes, and one shunt coil connected from the field terminal to ground. The armature rotates in bushings at both ends. An overrunning clutch drive is used to engage the cranking motor pinion with the flywheel. The overrunning action of the clutch protects the cranking motor armature from excessive speed when the engine starts.

A solenoid switch, integral with the solenoid assembly, operates the overrunning clutch drive by means of a linkage to the shift lever. When the ignition switch is turned to the starting position, the solenoid is energized, moving the cranking motor pinion into mesh with the flywheel. The solenoid switch contacts are then closed so that battery current is delivered to the cranking motor.

The drive gear housing has been extended to enclose the shift lever mechanism and plunger to protect them from exposure.

The armature shaft and clutch have spiral splines which prevent transmission of full cranking power until the clutch pinion is fully engaged in the fly­ wheel ring gear. An assist spring has been added between the armature winding and the collar of the clutch drive to aid the solenoid in overcoming the return spring force in the initial movement of the clutch. A pinion stop, consisting of a snap ring, retainer, and thrust collar assembled on the armature shaft takes all the end thrust.

1957 Oldsmobile Starter Motor Details



The starter switch is included in the ignition switch. The ignition key must be turned to the extreme clockwise position to energize the starter solenoid. Spring tension returns the key to the normal ignition position when it is released.



A neutral safety switch mounted on the mast jacket, is employed as a safety factor on Hydra­ Marie models. The switch prevents unintentional starting of the engine with the transmission in gear. The engine may be started with the selector lever in neutral or park position.





Checking Adjustment

  1. Apply hand brake firmly.
  2. Put shift lever into “D” range and turn ignition switch to “Start”.
  3. While holding ignition switch on “Start”, slowly move shift lever toward “N” position until engine cranks and starts.
  4. Without moving the shift lever after engine starts, depress accelerator pedal slightly to determine whether or not transmission is in gear.

If neutral safety switch is properly adjusted, transmission will not be in gear.



To adjust the neutral safety switch loosen the switch attaching screws on the mast jacket. With the selector lever in the Neutral position, position the switch so that a .090″ pin can be inserted through the hole in the switch arm and into the hole in the face of the switch. Tighten the switch attaching screws and remove the pin. Recheck adjustment as outlined under NEUTRAL SAFETY SWITCH, CHECKING ADJUSTMENT.





  1. Disconnect positive battery cable at junction block and disconnect the solenoid switch wire (purple) from the chassis wiring harness.
  2. Hoist car and remove engine filler plate.
  3. Disconnect starting motor from lower flywheel housing and remove motor while sliding battery cable loom through sleeve.



  1. Disconnect the field coil connector from the MOTOR solenoid terminal.
  2. Remove thru bolts, then remove commutator end frame and leather washer.
  3. Remove field frame assembly, armature, and clutch assembly from drive gear housing.
  4. If necessary to remove overrunning clutch from armature shaft proceed as follows:
    a. Remove thrust collar from armature shaft. (See Fig. 13-28)

    1957 Oldsmobile Overrunning Clutch Details

    b. Slide a standard half-inch pipe coupling or other metal cylinder of suitable size (an old pinion can be used if available) over shaft against retainer to be used as a driving tool. (See Fig. 13-29) With armature shaft supported on a wood block, tap end of driving tool until retainer clears snap ring.

    1957 Oldsmobile Removing Pinion Retainer

    c. Remove snap ring from groove in shaft using pliers or other suitable tool. If the snap ring is distorted during removal it will be necessary to use a new one upon reassembly.
    d. Remove retainer, clutch assembly, and assist spring from armature shaft.

  5. If necessary to replace brush holding parts, proceed as follows:
    a. Remove screws attaching leads and brushes to the holders.
    b. Press down on the flat spring so that center of spring clears the retaining slot. Slide off the brush spring and two brush holders as an as!’Jembly.
    c. Reassemble and install new brushes if necessary.
  6. If necessary to remove solenoid assembly or shift lever, proceed as follows:
    a. Remove solenoid to drive gear housing attaching screws, then remove solenoid assembly.
    b. To remove shift lever and/or plunger, remove shift lever pivot bolt.
    c. Disassemble shift lever from plunger.


Cleaning, Inspection and Testing of Starting Motor

  1. Clean all starting motor parts, but DO NOT USE GREASE DISSOLVING SOLVENTS FOR CLEANING THE OVERRUNNING CLUTCH, ARMATURE, AND FIELD COILS, since such a solvent would dissolve the grease packed in the clutch mechanism and would damage armature and field coil insulation.
  2. Test overrunning clutch action. The pinion should turn freely in the overrunning direction. Check pinion teeth to see that they have not been chipped, cracked, or excessively worn. Replace assembly if necessary.
  3. Check brush holders to see that they are not deformed or bent, but will properly hold brush es against the commutator.
  4. Check fit of armature shaft in bushing of drive housing. Shaft should fit snugly in the bushing. If the bushing is worn, it should be replaced.
  5. Inspect armature commutator. If commutator is rough or out-of-round, it should be turned down and the mica undercut 1/32″. Inspect the points where the armature conductors join the commutator bars to make sure that it is a good firm connection. A burned commutator bar is usually evidence of a poor connection.
  6. If test equipment is available:
    a. Check the armature for short circuits by placing on growler and holding hack saw blade over armature core while armature is rotated. If saw blade vibrates, armature is shorted. Recheck after cleaning between the commutator bars. If saw blade still vibrates, replace the armature.
    b. Using a 110-volt test lamp, place one lead on the armature core or shaft and the other on the commutator. If the lamp lights, the armature is grounded and must be replaced.
    c. Using a 110-volt test lamp, place one lead on each end of the three field coils connected in series. (See Fig. 13-30) If the lamp does not light, the field coils are open and will require repair or replacement.

    1957 Oldsmobile Checking Field Coil For Open

    d. Using a 110-volt test lamp, place one lead on the connector bar and the other on the field frame. (See Fig. 13-31) Disconnect the shunt coil ground before this check is made. If the lamp lights, the field coils are grounded and the defective coils will require repair or replacement.

    1957 Oldsmobile Checking Field Coil For Ground

    e. Using a 110-volt test lamp, place one lead on each end of the shunt coil. (See Fig. 13-32) Disconnect the shunt coil ground before this check is made. If the lamp does not light, the shunt coil is open and will require replacement.

    1957 Oldsmobile Checking Shunt Coil For Open

    f. Check the current draw of the solenoid windings. To check the current draw of the hold-in winding, connect a variable source of voltage (in series with an ammeter) to the switch terminal of the solenoid and ground. To check the current draw of both windings, ground the solenoid motor terminal, and connect a source of voltage (in series with an ammeter) to the switch terminal of the solenoid and ground.

CAUTION: Either of the above checks must be completed in a minimum length of time to prevent heating of the solenoid windings. Heating will cause the current draw readings to be below the specifications which are based on a temperature of 80°F.


Current Draw

Hold-In Winding (at 10 Volts) 10-12 Amps
Both Windings (at 10 Volts) 40-45 Amps


Solenoid Current Check

The solenoid windings can be tested with the solenoid either off or on the cranking motor. Two tests must be made to determine the current draw of both windings in parallel and of the hold-in winding alone. To test a current draw of both windings:

  1. Disconnect the lead from the terminal on the starter motor and ground the main solenoid terminal (which is normally connected to the starter motor) to the solenoid base with a jumper lead.
  2. Connect a source of variable voltage (battery and a variable resistance) in series with an ammeter between the solenoid base and the small solenoid switch terminal.
  3. Connect a voltmeter between the solenoid base and the small switch terminal.
  4. Adjust voltage to 10.0 volts. The current draw should be 40 to 45 amps at 80°F.

To check current draw of the hold-in winding, disconnect the jumper lead grounding the main solenoid terminal and readjust the variable resistance to obtain 10.0 volts. The current draw should be 10 to 12 amps. The small terminal may be checked for continuity by connecting a test light between this terminal and ground. With the solenoid in cranking position, the test light should indicate a complete circuit. (See Fig. 13-33)

1957 Oldsmobile Checking Solenoid Current Draw

NOTE: The above current-draw checks must be completed in a minimum length of time to pre­ vent heating of the solenoid windings. Heating will cause the current draw readings to be below the specifications which are based on a temperature of 80°F.

If the solenoid fails to pull in, the trouble may be due to excessive voltage drop in the solenoid control circuit. To check for this condition, turn the ignition switch to the start position and measure the voltage drop between the “BATTERY” terminal of the solenoid and the “SWITCH” terminal of the solenoid. If this voltage drop exceeds 2.5 volts excessive resistance in the solenoid circuit is indicated and should be corrected.

If the voltage drop does not exceed 2.5 volts and the solenoid does not pull in, measure the voltage available at the “SWITCH” terminal of the solenoid. It should pull in whenever the voltage avail­ able at the “SWITCH” terminal is 9 volts or more.

If above test does not meet specifications, the solenoid switch contacts and the contact disc should be checked for burned condition.



  1. If the solenoid assembly or shift lever was removed, proceed as follows:
    a. Assemble shift lever and plunger.
    b. Position shift lever and plunger assembly in drive gear housing and install lever pivot bolt.
    c. Install solenoid assembly to drive gear housing.
  2. If the overrunning clutch was removed from the armature shaft, assemble as follows:
    a. Lubricate drive end of armature shaft with SAE No. 10 oil, then install assist spring against armature.
    b. Slide clutch assembly on to armature shaft with pinion away from armature. (See Fig. 13-34)

    1957 Oldsmobile Overrunning Clutch Details (2)

    c. Slide retainer onto shaft with cupped surface facing away from clutch assembly.
    d. Install snap ring into groove on armature shaft.
    e. Assemble thrust collar on to shaft with shoulder next to snap ring.
    f. Position retainer and thrust collar next to snap ring. Using two pairs of pliers, grip retainer and thrust collar and squeeze until snap ring is forced into retainer and is held securely in groove in armature shaft. (See Fig. 13-35)

    1957 Oldsmobile Installing Retainer and Snap Ring

  3. Lubricate drive gear housing bushing with 4 or 5 drops of light engine oil.
  4. With thrust collar in place against snap ring and retainer, slide armature and clutch assembly into drive gear housing and engage clutch with shift lever yoke.
  5. Apply sealing compound on solenoid flange as shown in Fig. 13-36.

    1957 Oldsmobile Sealing Solenoid Housing To Frame

  6. Position field frame against drive gear housing using care to prevent damage to brushes.
  7. Lubricate commutator end frame bushing with 4 or 5 drops of light engine oil.
  8. Install leather washer on armature shaft and slide end frame on to shaft, then install and tighten thru bolts.
  9. Connect the field coil connector to the MOTOR solenoid terminal.
  10. Check pinion clearance as outlined under PINION CLEARANCE.


Pinion Clearance

Whenever the cranking motor has been disassembled or the solenoid has been replaced, it is necessary to check the pinion clearance. Pinion clearance must be correct to prevent the buttons on the shift lever yoke from rubbing on the clutch collar during cranking.

To check, connect a voltage source of approximately 6 volts between the solenoid switch terminal and ground.


Engergizing the solenoid to shift the clutch, push the pinion back as far as possible to take up any movement, and check the clearance with a feeler gauge. (See Fig. 13-37) The clearance should be .010″-.140″.

1957 Oldsmobile Checking Pinion Clearance

Means for adjusting pinion clearance is not pro­ vided on the 1957 starter motor. If the clearance does not fall within limits, check for improper installation and replace all worn parts.



Whenever the starter motor turns over slowly or not at all, or the solenoid f ails to engage the starter with the flywheel, excessive resistance of the starter circuit may be the ca use.

The following checks for excessive resistance can be performed with the starter motor on the car.

  1. Test battery and charge if necessary.

CAUTION: To prevent the engine from firing during the following checks, ground the distributor primary lead.

  1. Measure the voltage drop (V1) during cranking between the positive battery post and the “BATTERY” terminal of the solenoid. (See Fig. 13-38)

    1957 Oldsmobile Checking Starting Circuit Resistance

  2. Measure the voltage drop (V2) during cranking between the “BATTERY” terminal of the solenoid and the “MOTOR” terminal of the solenoid.
  3. Measure the voltage drop (V3), during cranking between the negative battery post and the starter motor frame.

If the voltage drop for any one of the above three checks exceeds 0.2 volt, excessive resistance is indicated in that portion of the starting circuit being checked. Locate and eliminate the cause f or any excessive voltage drop in these circuits in order to obtain maximum efficiency of the starting system.

If the solenoid fails to pull in, the trouble may be due to excessive voltage drop in the solenoid circuit. To check for this condition, measure the voltage drop (V4) during cranking, between the “BATTERY” terminal of the solenoid and the “SWITCH” terminal of the solenoid. If the voltage drop exceeds 2.5 volts, the resistance is excessive in the solenoid circuit.

If the voltage drop does not exceed 2.5 volts and the solenoid does not pull in, measure the voltage (V5) available at the “SWITCH” terminal of the solenoid. The solenoid should pull in with 9.0 volts at temperatures up to 200°F.



The ignition circuit (Fig. 13-39) includes the distributor, ignition coil, ignition resistor, ignition switch, spark plugs, and battery. (For ser v­ icing of the battery, see CHARGING C IRCU IT.)

1957 Oldsmobile Ignition System


DISTRIBUTOR (Fig. 13-40)

The external adjustment type distributor is a 12-volt, 8-cylind er unit. The cap has a window for adjusting point opening while the cap is mounted. The contact point set is replaced as one complete assembly. The service replacement contact set has the BREAKER L EVER SPR I N G TENSION and POINT ALIGNMENT pr e-adjusted. Only the POINT OPENING requires adjusting after replacement.

Under part throttle operation the intake manifold vacuum is sufficient to actuate the vacuum control diaphragm, thus advancing the spark and increasing fuel economy. During fast acceleration or when the engine is pulling heavily, the vacuum is not sufficient to actuate the diaphragm; therefor e the movable breaker plate is held so that the ignition timing is retarded.

The centrifugal advance mechanism consists of a cam actuated by two centrifugal weights con­ trolled by springs. As the speed of the distributor shaft increases with engine speed, the centrifugal advance weights move outward which advances the cam, causing the contact points to open earlier, thus advancing the spark.

1957 Oldsmobile Distributor Details



The external resistor, connected in series with the primary circuit between the battery and coil, limits the primary current at low speeds and allows the coil to operate at maximum efficiency at road speeds. The resistor is bypassed during cranking, thereby connecting the ignition coil directly to the battery. This makes full battery voltage available at the coil and keeps ignition voltage as high as possible during cranking. The bypassing of the resistor during cranking is accomplished within the ignition switch.



The ignition and starting switch is key-operated to close the ignition primary circuit and to energize the solenoid for cranking. Accessories, including electric windows, may be used when the engine is not running if the ignition key is turned to the extreme left position.



Type 44 spark plugs are used on 1957 Rocket engines. Plugs have 14mm. threads and 13/16″ hex body. The proper gap setting is .030″. Satisfactory results can be assured only when genuine AC plugs of the type recommended are used.

A neoprene nipple is installed on each spark plug to keep the spark plug porcelain clean and dry in all weather conditions.



The distributor and spark plugs are the only ignition system components that require periodic service. The remainder of the ignition system requires only periodic inspection to check operation of the units, tightness of the electrical connections, and condition of the wiring.



The hinge cap oiler should be filled with light engine oil at each vehicle lubrication period. When replacing contact point assembly and at every 6,000 mile interval apply a small amount of Delco-Remy Cam and Ball Bearing Lubricant or equivalent to the breaker cam. No other lubrication is required.

In addition to lubrication, the distributor requires periodic inspection of the cap, rotor, wiring breaker points, and timing.


Adjustment of Distributor Dwell Angle On The Car

  1. Remove the cap and inspect contact points; clean if necessary.
  2. Connect a dwell meter to the primary distributor lead terminal on the coil and a suit­ able ground.
  3. Disconnect temperature switch wiring to gain access to the distributor and raise access window on side of distributor cap.
  4. With the engine running at idle speed, insert dwell adjusting Tool J-6296 into the head of the adjusting screw as shown in Figure 13-41 and adjust dwell angle to 30°.

NOTE: If the dwell angle reading is erratic, check the primary circuit, points, and condenser.

The dwell angle variation should not exceed 3° at engine speeds between idle and 1750 R.P.M. Excessive variation indicates distributor wear.

1957 Oldsmobile Adjusting Dwell Angle


Spark Plugs

Whenever spark plugs are removed from the car and cleaned, the following precautionary steps should be followed to insure against voltage leak ­ age:

  1. The center electrode should be filed flat before the gap setting is made. (See Fig. 13-42)

    1957 Oldsmobile Filing Center Electrode

NOTE:   Do not file electrodes when setting gap on new plugs.

  1. Any traces of paint or dirt should be cleaned from the spark plug porcelain.
  2. All plugs should be checked for cracks in the porcelain. These cracks are not always visible because they may be hidden by the steel body. Use a spark plug tester to test plugs. Replacement must be made if cracks are found.



If the engine does not run, the ignition system may be at fault if:

  1. There is no spark during cranking when a spark plug wire is held 1/4″ from the engine.
  2. The engine starts but immediately stops when the ignition switch is released from the “START” position.

If the above checks indicate that the ignition system is at fault, the following checks may be made to help locate the difficulty, or locating trouble in the ignition system if the car runs, but not satisfactorily. (See Fig. 13-43 And IGNITION SYSTEM CHECK CHART) All checks are to be made with the lights and accessories off and in the sequence shown.

1957 Oldsmobile Ignition System Tests


1957 Oldsmobile Ignition System Check Chart


1957 Oldsmobile Conditions Pertraining to Ignition System Checks



Removal of Distributor

  1. Disconnect the distributor primary wire from coil.
  2. Remove distributor cap as shown in Fig. 13-44. Place screw driver in slot of latch, press down and turn 1/4 of a turn in either direction.
  3. Remove vacuum line from distributor.

NOTE: Check position of rotor so distributor can be installed in same position.

  1. Remove distributor clamp screw and hold down clamp; then remove distributor
  2. If necessary to remove secondary leads from distributor cap mark position on cap tower for lead to No. 1 cylinder. This will aid in re­ installation of leads in cap.

    1957 Oldsmobile Removing Distributor Cap


Distributor Tests (Removed from Car)

With the distributor removed from the vehicle, place the distributor in a distributor testing ma­ chine. When mounting distributor in tester, first secure the gear in the drive mechanism, then push distributor housing down toward the gear to take up end play between the gear and housing, and finally secure the housing in the tester. Test the distributor for variation of spark, correct centrifugal and vacuum advance (TEST SPECIFICATIONS), and condition of contact points. This test will give valuable information on the distributor condition and indicate parts replacement which may be necessary.


Replacing Distributor Contact Set

  1. Remove the two attaching screws which hold the base of contact set assembly in place. (See Fig. 13-45)

    1957 Oldsmobile Removing Contact Point Assembly

  2. Remove the condenser lead and primary lead from the contact set terminal by loosening the screw.
  3. Upon reassembly, install the primary leads as shown in Fig. 13-46. Leads must be properly located to eliminate lead interference between cap, weight base, and breaker advance plate.
  4. Apply a film of Delco-Remy Cam and Ball Bearing Lubricant, or equivalent, to the breaker cam.

    1957 Oldsmobile Contact Point Wiring


Adjusting Distributor Dwell Angle

  1. With distributor mounted in distributor testing machine, connect the dwell meter to the distributor primary lead.
  2. Turn the adjusting screw to set the dwell angle at 30°.

If a distributor tester is not available, the dwell angle may be adjusted as follows:

  1. Mount distributor in a vise.
  2. Connect a testing lamp between the primary lead and ground.
  3. Rotate the shaft until one of the circuit breaker cam lobes is under the center of the rubbing block of the breaker lever.
  4. Turn the adjusting screw clockwise until the lamp lights, then give the wrench one-haIf turn in the opposite direction.

When distributor has been installed in car, point opening must be reset by connecting a dwell meter to the primary distributor lead terminal on the coil and a suitable ground. The dwell angle must be set at 300 with the engine running at idle speed.



The rotor is retained by two screws and is pro­ vided with round and square lugs which engage with the mechanical advance plate so that the rotor may be installed in only one position. (See Fig. 13-47)

1957 Oldsmobile Rotor Installation (2)


Mechanical Advance

The mechanical advance weights and springs are accessible by removing the rotor. The mechanical advance plate is assembled to the breaker cam. In order to remove the breaker cam and advance plate, follow the procedure for VACUUM ADVANCE UNIT, REMOVAL.




  1. Remove the 2 vacuum advance attaching screws with an off-set screw driver.
  2. Turn the breaker plate clockwise and push the rod end of the vacuum advance down so that it will disengage and clear the breaker plate. Remove vacuum advance unit.


  1. Insert the rod end of the unit between the housing and the breaker plate.
  2. Turn the breaker plate clockwise so that the rod end can be inserted into the hole in the breaker plate.
  3. Install the attaching screws with the ground lead terminal under the inner mounting screw. (See Fig. 13-48)

    1957 Oldsmobile Installing Vacuum Advance




  1. Mark distributor shaft and gear so that they may be reassembled in the same position.
  2. File the staking from the driven gear pin and drive out the pin. (See Fig. 13-49)

    1957 Oldsmobile Removing Driven Gear Pin

  3. Pull the distributor assembly from the gear and pull the distributor shaft and breaker cam from the housing.
  4. Remove the snap ring from the upper bushing and lift the breaker plate and felt wick from the bushing (See Fig. 13-50)

    1957 Oldsmobile Removing Breaker Plate

  5. Remove the two retaining screws and the vacuum advance.



  1. Install the vacuum advance with the ground lead terminal under the inner mounting screws. (See Fig. 13-48)
  2. Place the felt wick on the upper bushing, then place the breaker plate over the upper bushing and vacuum advance link.
  3. Install the snap ring on the upper bushing.
  4. Slide the distributor shaft through housing bushings.
  5. Push the distributor shaft into the driven gear with the holes aligned.
  6. Install and stake a new pin. Exercise care while staking to prevent damaging the gear.
  7. Lubricate distributor as outlined und er PERIODIC SERVICE and check and adjust dwell angle, vacuum advance, and mechanical advance. Refer to ELECTRICAL SPECIFICATIONS (Distributor).




When analyzing faulty horn operation, of either two conditions may be found.

  1. Horn will not operate or operates intermittently.
  2. Horn has poor tone.


Horn Will Not Operate or Operates Intermittently

These conditions may result from:

  1. Defective relay, horn button, or wiring.
  2. Defective horn (See Current Adjustments)

Connect a jumper wire to the “H” and “B” terminals of the relay. (See Fig. 13-51) If the horn operates, the defect is in the relay, horn button, or wiring.

1957 Oldsmobile Checking Horn Relay Closing Voltage

Ground the “S” terminal of the relay. If the horn operates, either the horn button or the wiring is at fault. If the horn does not operate and the wiring between the battery and the re­ lay is not defective, connect a voltmeter be­ tween the horn terminal and ground. Connect the jumper wire to the “H” and “B” terminals of the relay and note the reading on the volt­ meter.

If the voltmeter shows no reading, the wiring between the relay and the horn is open or the horn is not grounded. If the reading is less than 7.0 volts, the fault is high resistance in the wiring or a faulty horn. If the reading is over 7.0 volts, the horn is defective, and the current adjustment should be checked.

Horn Operates But Has Poor Tone-

This condition may result from:

  1. Loose connections in the horn relay or horn circuit.
  2. Defective horn button.
  3. Defective relay (See Horn Relay Checks and Adjustments)
  4. Defective horn (See Current Adjustment)



Connect an ammeter and a voltmeter as shown in Fig. 13-52. With the horn operating the current draw should be 8.0 to 10.0 amps at ll.5 volts. To change the current adjustment turn the adjusting screw clockwise to increase and counter-clockwise to decrease.

1957 Oldsmobile Horn Current Adjustment

If the horn fails to operate properly after the above checks and adjustments have been made, the horn should be replaced.



NOTE: Disconnect battery during air gap and contact point opening checks.


Air Gap

Check the air gap (.014″) with points barely touching. (See Fig. 13-53) If necessary to adjust, bend low er point support.

1957 Oldsmobile Checking Horn Relay Air Gap


Contact Point Opening

The contact point opening should be.027″. Adjust by bending upper armature stop. (See Fig. 13-54)

1957 Oldsmobile Adjusting Horn Relay Contact Point Opening


Closing Voltage

Connect a variable resistance of at least 10 ohms in series with the relay “B” terminal and connect a voltmeter across the “S” and “B” terminal as shown in Fig. 13-51. Slowly decrease the resistance until the points close. Closing voltage should be 5.0 to 9.0. If the voltage is out­ side this range, adjust to 6.5 volts by bending the armature spring post down to increase the voltage or up to decrease the voltage. (See Fig. 13-55)

1957 Oldsmobile Adjusting Horn Relay Closing Voltage

NOTE: If relay terminals are not marked, refer to Fig. 13-51 for terminal identifications.



The frequency of the turn signals (80 to 100 flashes per minute) is controlled by a non-adjustable make-and-break switch, or “flasher unit”. If the turn signal pilot light fails to operate, check for burned-out bulbs in the parking light, taillight, or instrument cluster, and for loose connections. If the flasher unit is inoperative it must be replaced.

The turn signal switch is located on the mast jacket below the instrument panel. See STEERING SECTION for servicing of the turn signal collar.



To adjust the turn signal switch, loosen the switch attaching screws, and with the lever in the neutral position, shift the switch until two.090″ pins can be inserted into the holes on the face of the switch. (See Fig. 13-56)

1957 Oldsmobile Adjusting Turn Signal Switch



The gasoline gauge consists of an electrical instrument in the cluster and a float-controlled rheostat in the tank. These two units can be checked for accuracy with Tester BT-100.



  1. Connect Tester BT-100 between gas tank unit wire (in trunk) and ground as shown in Fig. 13-57.
  2. Set Tester on “E”.
  3. Start engine and check reading on instrument cluster gauge. Gauge should read within 1/16″ of “E” position.
  4. Set t ester at “1/2” calibration position.
  5. Turn off ignition and restart engine. Gauge should read within 1/16″ of “1/ 2” position.
  6. Repeat procedure for “F” position.

    1957 Oldsmobile Checking Fuel Gauge

NOTE: If gauge registers correctly, the trouble is in the tank un it. If it does not register correctly, the trouble may be in either the wiring or the cluster gauge.

If cluster gauge and wiring are alright:

  1. Drop gas tank and remove tank unit. Clean all dirt from around tank unit terminal.
  2. Connect tank unit to cluster gauge lead and ground tank unit to any part of the car.
  3. Turn ignition on and move the float arm up and down. If the unit is operative, the cluster gauge will give readings corresponding to the position of the arm. Check the freedom of movement of the float arm.
  4. If unit is to be replaced, always check the new unit as outlined in Step 3 before installing in the tank.

If the cluster gauge or wiring are faulty, re­ move the plastic “snap-on” cap from the right hand terminal of the cluster gauge. (See Fig. 13-58) Connect the tester between the terminal and ground. Test gauge as outlined above. If gauge operates correctly, the wiring is at fault. If not, replace gauge.

NOTE: If gauge registers full regardless of the position of the tank float, an open circuit is indicated.

1957 Oldsmobile Checking Cluster Gauge



The engine temperature indicator lights are controlled by a thermal switch in the rear part of the left hand cylinder head.

When the ignition switch is turned to the “START” position a test circuit is closed to indicate whether the red light is functioning properly. (See Fig. 13-59) When the engine is started cold, the green light comes on to indicate that the engine has not reached nor ma l operating temperature (113°F ± 2°F). When the engine reaches the nor­ m al temperature the green light will be turned off by the thermal switch.

If the engine cooling system is not functioning properly, the thermal switch will close the circuit to the red light when the engine temperature reaches 232°F ± 2°F. The thermal switch does not require servicing. If it is defective, it should be replaced.

1957 Oldsmobile Temperature Indicator Circuit



The engine oil filter mounting pad houses a pressure-operated switch which completes the circuit for the oil pressure warning light. When the engine is running, the light operates only when the oil pressure is not satisfactory. This light should come on when the ignition is turned on and the engine is not running.

1957 Oldsmobile Gauge Oil Pressure Switch



If, when the ignition key is turned to the “on” position, the warning lamps do not operate and the fuel gauge does not register “E” or above, the SFE 9 amp. fuse in the yellow circuit is blown. (See Fig. 13-2)



HEADLAMPS (Fig. 13-61)

1957 Oldsmobile Headlamp Assembly

Remove and Replace Unit

  1. Remove head lamp rim.
  2. Disengage the coil spring from the retaining ring, and remove the assembly.
  3. Spring retaining ring to disengage rim of sub­ body from top lug on retaining ring and re­ move sub-body. (See Fig. 13-62)
  4. Remove “Sealed Beam” unit from retaining ring.

    1957 Oldsmobile Sub-Body Removal

To Replace Unit:

  1. Place “Sealed Beam” unit in retaining ring so that the top of the unit aligns with the diagonally slotted tab on the retaining ring.
  2. Install sub-body by inserting flange under bottom retaining lug in retaining ring and snapping into position under side and top retaining lugs.
  3. Place assembly in the body and engage the slotted retaining tabs with the slots in the two adjusting screws.
  4. Engage the coil spring with the retaining ring.
  5. Replace headlamp rim.



Guide T-3 headlamps are designed to permit quick, accurate adjustment using the Guide T-3 Safety Aimer.

NOTE: Some states require a loading allowance for headlamp aiming.

  1. Adjust aimers and make sure car is sitting on a level floor
  2. Remove head lamp rims.
  3. Mount aimers on lamps so that cross arms are horizontal. Aimer with attached string goes on left lamp.
  4. Fasten the spring-loaded string to the right hand aimer arm. Rotate aimers until the string is lined up with points “F” and “G”. (See Fig. 13-63)
  5. Rock the car to equalize the springs.
  6. Horizontal Aim:
    a. Loosen left horizontal adjusting screw “A” and tighten until string just touches point “F”. (See Fig. 13-63)

    1957 Oldsmobile Horizontal Aim

    b. Repeat adjustment on screw “AA” on right hand lamp until string just touches point “G”.
    c. Recheck points “F” and “G” and readjust if necessary.

  7. Vertical Aim:
    a. Loosen vertical adjusting screws and tighten until bubbles are centered in level. (See Fig. 13-64)
  8. Recheck string at points “F” and “G” and readjust if necessary.

NOTE: Always turn adjusting screws clock­ wise when making the final adjustments. Upper and lower beams are adjusted simultaneously by the above procedure.

1957 Oldsmobile Vertical Aim


Headlamp Body

The headlamp body is attached to the fender with sheet metal screws and sealed with an auto-body sealer between the body and the fend er. (See Fig. 13-65)

1957 Oldsmobile Headlamp Housing



The tail lamp bulb is a double contact, double element bulb which acts as stop light, tail light, and turn signal light. (See Fig. 13-66 for tail lamp assembly details).

1957 Oldsmobile Tail Lamp Assembly


STOP LIGHT SWITCH (Standard Brake)

The stop light switch used with the standard brake is attached to the underside of the toe pan, and is actuated by the movement of the brake pedal. If the stop light switch does not operate properly, it should be replaced.



The stop light switch used with the pow er brake is mounted on the brake pedal bracket. Adjustment is made with an adjustable contact screw. (See Fig. 13-67) To obtain proper operation of the stop lights, adjust the screw as follows:

  1. With brake pedal in the fully released position, turn adjusting screw until stop lights just go “off”; then turn adjusting screw four turns toward switch to obtain proper adjustment.
  2. Check stop light switch operation by applying and releasing the brake, making certain that stop lights go “off” when brake pedal is in fully released position.

    1957 Oldsmobile Power Brake Stoplight Switch



On cars equipped with Hydra-Matic the back-up lamp switch is incorporated with the neutral safety switch. (See STARTING CIRCUIT, Neutral Safety Switch, for adjustment). On cars equipped with Syncro-Mesh transmissions the back-up lamp switch is mounted on the left hand engine mount. (See Fig. 13-68) To adjust the switch loosen the mounting bolts and move the switch to obtain.100″ clearance between the switch lever and the switch arm when the transmission is in second gear.

1957 Oldsmobile Back-Up Lamp Switch



The headlight system is controlled by the head­ light switch on the instrument panel and the foot­ operated beam selector, or “dimmer ” switch. Cars equipped with the Autronic Eye have a com­ bination override and “dimmer” switch and a light switch which includes a separate ON-OFF control for the Autronic Eye. The foot dimmer switch must be in the high beam position before the Autronic Eye will operate.

The head lamps and the headlamp switch are protected by a circuit breaker. The instrument panel lights and the illuminated escutcheons are controlled by a rheostat built into the light switch. Turning the knob of the light switch operates the rheostat. The rheostat and the panel light circuit are protected by a 3 amp fuse located on the light switch. (See Fig. 13-69)

1957 Oldsmobile Headlamp Switch



The normal lighting load is not sufficient to cause the circuit breaker to open. If a short occurs the circuit breaker will cause the head­ lamps to flicker. This flickering will continue until the cause of the short is corrected. The circuit breaker is not adjustable.




Aiming Device AE-4 must be used with test lamp on model AE Tester for making adjustments as shown in Fig. 13-70.

  1. Remove phototube unit cover and lens.
  2. Install the test lamp with adapter ring in lens slot with locator notch down.

CAUTION: Aiming Device AE-4 contains a special filter to permit the use of same meter settings on model AE-1 or AE-2 Tester for 1952 thru 1955 “Autronic-Eye” units. Do not damage filter. When not in use, Aiming Device AE-4 should be properly stored in its case to protect the filter from dust and foreign particles. If the filter or any component of Aiming Device AE-4 becomes damaged, the whole unit should be returned to the supplier.

  1. Replace original cover with Aiming Device AE-4.
  2. Tighten both phototube unit screws.

    1957 Oldsmobile Aiming Device AE-4 in Position


Vertical Aiming Adjustment

  1. Phototube unit aiming should be done with car unloaded, with trunk empty except for spare tire, preferably with gas tank at least haIf full, and with correct tire pressure.
  2. Position car on a level floor. Floor must be level within 1/4″ fore and aft of car.
  3. Rock car gently sideways to equalize springs.
  4. Adjust aiming dial on the Aiming Device to the number stamped on the name plate on bottom side of phototube unit.
  5. Adjust phototube unit aiming screw until bubble is centered in level.

NOTE: If the phototube unit is aimed too low, back reflections from the headlamps of the car on which the “Autronic-Eye” is installed will hold its own headlamps on the lower beam. Also, the phototube unit must be aimed as low as possible to provide the maximum tolerance for car loading.


Horizontal Aiming Adjustment

NOTE: If the phototube unit has been removed for service, the mounting holes in the instrument panel may allow it to be reinstalled with the HORIZONTAL AIM mispositioned. The center line of the phototube unit must be aimed parallel to the center line of the car after the installation is made.

  1. Place two pieces of tape or chalk marks 24-1/2″ apart on a wall or screen at hood level height. (See Fig. 13-71)
  2. Line up the hood molding with the right hand tape or chalk mark. The car must be positioned perpendicular to and 25 feet from the wall or screen.
  3. Remove cover and replace with Aiming Device AE-4.
  4. Aim over sights to the left hand tape.

NOTE: If the unit is aimed more than 4 inches to the right or left of the left hand tape, reset phototube. In some cases it may be necessary to elongate one of the mounting stud holes in the instrument panel.

1957 Oldsmobile Horizontal Aim (2)


Hold Sensitivity Test

CAUTION: Turn headlamps “Off” before re­ moving cover from the phototube unit. The “Autronic-Eye” develops 800 volts.

  1. Install Aiming Device AE-4 according to instructions under Mounting of AE-4 Kit.
  2. Turn headlamps, and Autronic Eye “On” and WAIT AT LEAST FOUR MINUTES for amplifier to stabilize. Set standard foot dimmer switch to “Automatic” position. Upper beam will then be on.
  3. Turn Zero Corrector on face of meter until meter pointer is on zero set line.
  4. Turn Intensity Rheostat of tester counterclockwise.
  5. Insert tester connector into cigar lighter receptacle.
  6. Operate engine at fast idle while making sensitivity tests and adjustments.
  7. Turn Tester Selector Switch to “Dim” position. (Be sure to use proper “Dim” position for clear or tinted windshield.)
  8. Turn Intensity Rheostat all the way clockwise to end of adjustment to obtain a lower beam.
  9. Turn tester Selector Switch to “Hold” position.
  10. Slowly tum Intensity Rheostat counter-clock­ wise just to point where headlamps switch to upper beam. The m et er pointer should now read in the Hold Sensitivity Adjustment Bar on the meter scale.

If Hold Sensitivity is not properly adjusted, proceed with Hold Sensitivity Adjustment.


Hold Sensitivity Adjustment

The Hold and Dim adjustments are knurled finger -tip controls located on the underside of the amplifier unit. The location of each is indicated by a stamp on the amplifier cover. (See Fig. 13-72) THE DIM SENSITIVITY ADJUSTMENT MUST NOT BE MADE UNTIL AFTER THE HOLD SEN­ SITIVITY IS CORRECTLY ADJUSTED.

1957 Oldsmobile Hold and Dim Adjustments

NOTE: A “fish-paper” retainer is pressed over the knurled adjusting knobs after the initial setting is made at the factory. The “fish-paper” retainer should be removed and DISCARDED when­ ever adjustments are necessary.

  1. Turn Hold adjustment clockwise to end of adjustment.
  2. Rotate Intensity Rheostat all the way clockwise.
  3. Turn Selector momentarily to “Dim” position to switch lights to low er beam, then switch back to “Hold” position.

NOTE: If lights do not switch to low er beam, the “Dim” control must be turned clock­ wise to end of adjustment and then readjusted after Hold adjustment is correct.

  1. Adjust tester Intensity Rheostat until meter point er is in center of Hold Sensitivity Bar.
  2. Turn the Hold control counter -clockwise SLOWLY just to the point where headlamps switch to upper beam.
  3. Rotate tester Intensity Rheostat clockwise to end of travel, then turn Selector Switch momentarily to “Dim” position and back to “Hold”. (Headlamps should now be on lower beam.)
  4. Recheck Hold adjustment by turning Intensity Rheostat SLOWLY counter-clockwise just to point where headlamps switch to upper beam. Meter pointer should now be aligned with the right hand edge of “Hold” adjustment green bar if adjustment is correct. (See Fig. 13-73) If not, repeat procedure starting with Step 1.

    1957 Oldsmobile Meter Reading For Hold Adjustment


Dim Sensitivity Test

  1. Rotate tester Intensity Rheostat completely counter -clockwise.
  2. Tum Selector Switch to “Dim” position. Headlamps should now be on upper beam.
  3. Turn Intensity Rheostat SLOWLY clockwise stopping at the exact point where the headlamps switch to lower beam. Meter pointer should read within the Dim Sensitivity Adjustment Line.

If Dim Sensitivity is not properly adjusted, proceed with Dim Sensitivity Adjustment.


Dim Sensitivity Adjustment

  1. Rotate Dim control completely counter-clockwise. (See Fig. 13-72)
  2. Momentarily turn tester “Off”, then back to “Dim” position. Headlamps should now be on upper beam.
  3. Adjust Intensity Rheostat until meter pointer reads in the right hand edge of the Dim Sensitivity Adjustment Line.
  4. SLOWLY rotate Dim control clockwise just to point where headlamps switch to lower beam. DO NOT GO BEYOND THIS SETTING.
  5. Turn tester Intensity Rheostat completely counter-clockwise then momentarily turn tester to “Off” and back to “Dim”.
  6. Rotate tester Intensity Rheostat SLOWLY clockwise just to point where headlamps switch to lower beam. Meter will read within Dim Sensitivity Line if adjustment is correct. If not, repeat steps 1 thru 5.
  7. Turn off headlights and disconnect tester from cigar lighter receptacle.
  8. Remove tester and Aiming Device AE-4 from phototube unit. Replace lens, cover and screws.

1957 Oldsmobile Instrument Panel Wiring


1957 Oldsmobile Electrical Torque Specifications



1957 Oldsmobile Electrical Specifications


1957 Oldsmobile Electrical Distributor Specifications


1957 Oldsmobile Electrical Specifications 2


1957 Oldsmobile Electrical Specifications 3


1957 Oldsmobile Fuse Specifications