In-Vehicle Testing - Charging System

1. Visually check belt and wiring and make any necessary repairs.
2. On models equipped with charge indicator light, turn ignition switch to On position (engine stopped), lamp should be on. If not, disconnect harness from alternator, and ground L terminal.
a. If lamp lights, replace alternator.
b. If lamp does not light, locate open circuit between grounding lead and ignition switch and check for defective indicator light bulb.

3. On models equipped with charge indicator light, with ignition switch on and engine running at a moderate speed, lamp should be off. If not, disconnect wiring harness from alternator.
a. If lamp goes off, replace alternator.
b. If lamp stays on, check for grounded L terminal in wiring harness.

4. On all models, check for battery over-charging or under-charging as follows:
a. Disconnect wiring harness connector from alternator.
b. With ignition switch on and engine not running, connect voltmeter from ground to L terminal.
c. Zero reading indicates open circuit between terminal and battery. Correct as required.
d. Reconnect harness connector to alternator.
e. Measure voltage across battery terminals with engine running at approximately 2000 RPM. If voltage is above 16 volts, replace alternator.
f. Turn on accessories and load battery with carbon pile to obtain maximum amperage. Maintain voltage at 13 volts or less. If alternator is within 15 amps of rated output, it is acceptable.