Troubleshooting Guide

Initial Starter Diagnosis (Begin With This Test)

NOTES:
a. If the starter cranks the engine slowly or not at all, several preliminary checks should be made to determine whether the trouble lies in the battery, in the starter, in the wiring between them, or elsewhere. Many conditions besides defects in the starter itself can result in poor cranking performance.
b. To make a quick check of the starter system, turn on the headlights. They should burn with normal brilliance. If they do not, the battery may be run down.
c. If the battery is in a charged condition so that lights burn brightly, operate the starting motor. Any one of three things will happen to the lights: they will go out, they will dim considerably or they will stay bright without any cranking action taking place.

STARTER MOTOR DOES NOT OPERATE AT ALL
1. Check starter coil.
2. Check for poor contact at battery terminals and starter.
3. Check inhibitor switch.
4. Check clutch pedal switch.
5. Check starter relay.
6. Check theft-alarm starter relay.
7. Check key reminder switch.

IF LAMP GOES OUT

If the lamps go out as the starter switch is closed, it indicates that there is a poor connection between the battery and starting motor. This poor connection will most often be found at the battery terminals. Correction is made by removing the cable clamps from the terminals, cleaning the terminals and clamps, replacing the clamps and tightening them securely. A coating of corrosion inhibitor (petroleum jelly will do) may be applied to the clamps and terminals to retard the formation of corrosion.

IF LAMP DIMS

If the lamps dim considerably as the starter switch is closed and the starter operates slowly or not at all, the battery may be run down, or there may be some mechanical condition in the engine or starting motor that is putting a heavy load on the starting motor. This imposes a high discharge rate on the battery which causes noticeable dimming of the lamps.
Check the battery state of charge. If it is charged, the trouble probably lies in either the engine or starting motor itself. In the engine, tight bearings or pistons or heavy oil place an added burden on the starting motor. Low temperatures also hamper starter motor performance since it thickens engine oil and makes the engine considerably harder to crank and start. Also, a battery is less efficient at low temperatures.
In the starting motor, a bent armature, loose pole shoe screws or worn bearings, any of which may allow the armature to drag, will reduce cranking performance and increase current draw.
In addition, more serious internal damage is sometimes found. Thrown armature windings or commutator bars, which sometimes occur on overrunning clutch drive starting motors, are usually caused by excessive overrunning after starting. This is the result of such conditions as the driver keeping the starting switch closed too long after the engine has started, the driver opening the throttle too wide in starting, or improper carburetor fast idle adjustment. Any of these subject the overrunning clutch to extra strain which may cause it to seize, spinning the armature at high speed with resulting armature damage.
Another cause may be engine backfire during cranking which may result, among other things, from ignition timing being too far advanced.
To avoid such failures, the driver should pause a few seconds after a false start to make sure the engine has come completely to rest before another start is attempted. In addition, the ignition timing should be checked if engine backfiring has caused the trouble.

LAMP STAYS BRIGHT, NO CRANKING ACTION

This condition indicates an open circuit at some point, either in the starter itself, the starter switch or control circuit. The solenoid control circuit can be eliminated momentarily by placing a heavy jumper lead across the solenoid main terminals to see if the starter will operate. This connects the starter directly to the battery and, if the starter operates, indicates that the control circuit is not functioning normally. The wiring and control units must be checked to locate the trouble.
If the starter does not operate with the jumper attached, it will probably have to be removed from the engine so it can be examined in detail.