Field Circuit Drain Test

Charging System Schematic:

Charging System Tests
When performing charging system tests, turn OFF all lamps and electrical components. Place transmission in NEUTRAL and apply parking brake.

CAUTION: Do not make jumper wire connections except as directed. To do so may damage regulator.

NOTE: Battery posts and cable clamps must be clean and tight to ensure accurate meter indications.





Field Circuit Drain
Connect the voltmeter negative lead to the alternator rear housing for all of the following voltage readings:
1. With ignition switch turned to OFF position, contact voltmeter positive lead to regulator F terminal screw. The meter should indicate battery voltage if system is operating normally. If less than battery voltage is indicated, proceed with Step 2 to find cause of current drain.

Regulator F Terminal Location:

2. Disconnect wiring plug from regulator and contact voltmeter positive lead to wiring plug I terminal. NO voltage should be indicated. If voltage is indicated, service I lead from ignition switch to identify and eliminate voltage source.
3. If no voltage was indicated in Step 2, contact voltmeter positive lead to wiring plug S terminal. NO voltage should be indicated. If NO voltage is indicated, replace the regulator.
4. If voltage was indicated in Step 3, disconnect wiring plug from the alternator rectifier connector. Again, contact voltmeter positive (+) lead to regulator wiring plug S terminal. If voltage is indicated, service S lead to alternator plug to eliminate voltage source. If NO voltage is indicated, replace alternator rectifier assembly.