Regulator S and/or I Circuit 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.





Regulator S and/or I Circuit Test
1. Disconnect the wiring plug from the regulator. Connect a jumper wire from the regulator A terminal to the wiring plug A lead. Add a jumper wire from the regulator F screw to the alternator rear housing.
2. With the engine idling and the voltmeter negative lead connected to battery ground terminal, connect the voltmeter positive lead to the S terminal and then to the I terminal of the regulator wiring plug. The voltage at the S circuit should read approximately one-half that of the I circuit. If voltage readings are normal, remove the jumper wire. Replace the regulator and connect the wiring plug to the regulator. Repeat the Load Test after servicing.
3. If NO voltage is present, remove the jumper wire and service the faulty wiring circuit or alternator.
4. Connect the voltmeter positive lead to the positive battery terminal. Connect the wiring plug to the regulator. Repeat the Load Test.