Voltage Drop Tests

The following test procedures will be performed with the starter motor on the vehicle.

Motor Feed Circuit

NOTE: Make all multimeter connections at the component terminal rather than the cable or wiring terminal.

1. Disconnect the ignition coil connector from the ignition coil.
2. Connect a remote starter switch between the starter solenoid S-terminal and the battery positive (+) post.
3. Connect the positive (+) lead of the 73 Digital Multimeter to the battery positive (+) Post. Connect the negative (-) lead of the multimeter to the starter solenoid M-terminal.
4. Engage the remote starter switch. The multimeter reading should be 0.5 volts or less.
5. If the voltage at the M-terminal is greater than 0.5 volts, move the multimeter negative (-) lead to the starter solenoid B-terminal and repeat the test.
6. If the voltage reading at the B-terminal is less than 0.5 volts, the problem is either in the connections at the starter solenoid or the starter solenoid.
7. Remove the wires at the starter solenoid B-, S-, and M-terminals. Clean the connections and install the cables. Apply dielectric grease to inhibit corrosion to the S-terminal. Repeat steps 1 through 5 above. If the reading is still higher than 0.5 volts at the M-terminal and 0.5 volts or lower at the B-terminal, the problem is in the starter solenoid. Replace the starter motor.

NOTE: When disconnecting the plastic hard shell connector at the starter solenoid S-terminal, grasp the plastic connector, depress the plastic tab, and pull off the lead assembly. Do not pull on the lead wire or damage may result.

8. If the voltage taken at the starter solenoid B-terminal is greater than 0.5 volts, the problem is either the positive (+) battery cable connection or the positive (+) battery cable.

Motor Ground Circuit

NOTE: Make all multimeter connections at the component terminal rather than the cable or wiring terminal.

A slow cranking condition can be caused by resistance in the ground or return portion of the cranking circuit. Check the voltage drop in the ground circuit as follows:
1. Disconnect the ignition coil connector from the ignition coil.
2. Connect a remote starter switch between the starter solenoid S-terminal and the battery positive (+) terminal.
3. Connect the positive (+) lead of a 73 Digital Multimeter to the starter motor housing. The connection must be clean and free of rust or grease. Connect the negative (-) lead to the negative (-) battery terminal.
4. Engage the remote starter switch and read the voltage. The reading should be 0.2 volts or less.
5. If the voltage drop is greater than 0.2 volts, clean the negative (-) battery cable connections at the battery and chassis. Also, clean the engine ground cable connection at the cable mounting bracket. If the voltage drop is still excessive, repair or replace the battery ground cable.