Generator On-Vehicle Tests
GENERATOR ON-VEHICLE TESTSCAUTION:
- To prevent damage to the generator, do not make jumper wire connections except as directed.
- Do not allow any metal object to come in contact with the housing and the internal diode cooling fins with the key in the ON or OFF positions. A short circuit may result and burn out the diodes.
NOTE:
- Battery posts and cable clamps must be clean and tight for accurate meter indications.
- Refer to the battery tester manual for complete directions for testing the charging system.
1. Turn off all lamps and electrical components.
2. Place the transmission in NEUTRAL and apply the parking brake.
3. Carry out the Load Test and No Load Test according to the following component tests:
Generator On-vehicle Tests - Load Test
1. Switch the tester to the ammeter function.
2. Connect the positive and negative leads of the tester to the corresponding battery terminals.
3. Connect the current probe to the generator B+ output terminal, circuit SDC02 (RD).
Expedition And Navigator:
4. With the engine running at approximately 2,000 rpm, adjust the tester load bank to determine the output of the generator. Generator output should be greater than the graph shown. If not, refer to the pinpoint test or GO to Symptom Chart. Pinpoint Tests Symptom Related Diagnostic Procedures
Generator On-vehicle Tests - No Load Test
1. Switch the tester to the voltmeter function.
2. Connect the voltmeter positive lead to the generator B+ terminal, circuit SDC02 (RD) and the negative lead to ground.
3. Turn all of the electrical accessories off.
4. With the engine running at approximately 2,000 rpm, check the generator output voltage. The voltage should be between 13.2 and 15.5 volts. If not, refer to the pinpoint test or GO to Symptom Chart. Pinpoint Tests Symptom Related Diagnostic Procedures