Circuit/System Testing
- Verify that a test lamp illuminates between the generator B+ and ground.
- If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
NOTE: Some vehicles use a maxi fuse or a fuseable link for this circuit, this circuit must be tested before diagnosing any charging system issues. - Ignition ON, verify that no generator or battery current sensor DTCs are set that would cause a charging system concern.
- If DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Ignition OFF, measure the voltage across the battery terminals. The voltage should read 12.0 V or greater at room temperature.
- If not within specified value, refer to Battery Inspection/Test .
- Connect a carbon pile tester to the battery.
- Start the engine and increase the engine speed to 2,500 RPM. Observe the voltage reading on the tester. The voltage should read between 12.6-15.0 V.
- If not within specified range, replace the generator.
- Adjust the carbon pile tester to the specified load test output value, refer to Generator Usage .
- If not within specified value, replace the generator.