Starter motor

Correct starter motor operation can be confirmed by performing the following free running bench test.

This test can only be performed with the starter motor removed from the vehicle. Refer to Starting  System in the Specifications section of this group for the starter motor specifications.

(1) Remove the starter motor from the vehicle.

Refer to Starter Motor in the Removal and Installation section of this group for the procedures.

(2) Mount the starter motor securely in a softjawed bench vise. The vise jaws should be clamped on the mounting flange of the starter motor. Never clamp on the starter motor by the field frame.

(3) Connect a suitable volt-ampere tester and a 12-volt battery to the starter motor in series, and set the ammeter to the 100 ampere scale. See the instructions provided by the manufacturer of the volt-ampere tester being used.

(4) Install a jumper wire from the solenoid terminal to the solenoid battery terminal. The starter motor should operate. If the starter motor fails to operate, replace the faulty starter motor assembly.

(5) Adjust the carbon pile load of the tester to obtain the free running test voltage. Refer to Starting System in the Specifications section of this group for the starter motor free running test voltage specifications.

(6) Note the reading on the ammeter and compare this reading to the free running test maximum amperage draw. Refer to Starting System in the Specifications section of this group for the starter motor free running test maximum amperage draw specifications.

(7) If the ammeter reading exceeds the maximum amperage draw specification, replace the faulty starter motor assembly.

STARTER SOLENOID

This test can only be performed with the starter motor removed from the vehicle.

(1) Remove the starter motor from the vehicle.

Refer to Starter Motor in the Removal and Installation section of this group for the procedures.

(2) Disconnect the wire from the solenoid field coil terminal.

(3) Check for continuity between the solenoid terminal and the solenoid field coil terminal with a continuity tester (Fig. 7). There should be continuity. If OK, go to Step 4. If not OK, replace the faulty starter motor assembly.

(4) Check for continuity between the solenoid terminal and the solenoid case (Fig. 8). There should be continuity. If not OK, replace the faulty starter motor assembly.

Fig. 7 Continuity Test Between Solenoid Terminal and Field Coil Terminal - Typical

1 - OHMMETER

2 - SOLENOID TERMINAL

3 - FIELD COIL TERMINAL

Fig. 8 Continuity Test Between Solenoid Terminal and Solenoid Case - Typical

1 - SOLENOID TERMINAL

2 - OHMMETER

3 - SOLENOID