Generator on-Vehicle Tests

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

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

LOAD TEST
1. Switch the Alternator, Regulator, Battery and Starter Tester (ARBST) to the ammeter function.
2. Connect the positive and negative leads of the Alternator, ARBST to the battery.
3. Connect the current probe to the generator B+ output lead, circuit 38 (BK/O).
4. With the engine running at 2000 rpm, adjust the Alternator, ARBST load bank to determine the output of the generator. Generator output should be greater than the applicable graph shown. If it is not, refer to the Symptom Chart. Symptom Related Diagnostic Procedures





95 Amp Generator





130 Amp Generator

NO-LOAD TEST
1. Switch the ARBST to the voltmeter function.
2. Connect the voltmeter positive lead to the generator B+ terminal and the negative lead to ground.
3. Turn all electrical accessories off.
4. With the engine running at 2000 rpm, check the generator output voltage. The voltage should be between 13-15 volts. If not, refer to the symptom chart. Symptom Related Diagnostic Procedures