Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the generator.
- Ignition ON, and the engine OFF, connect a test lamp to battery positive voltage and repeatedly probe the generator field duty cycle circuit, harness side while monitoring the GEN-F Terminal Signal Parameter in the ECM data list. It should change from 0 percent to above 95 percent.
- If the GEN-F Terminal Signal parameter was not affected by the test lamp, test the GEN-F Terminal Signal circuit for a short to voltage, short to ground, a high resistance, or an open circuit. If the circuit tests normal, replace the ECM.
- Go to Charging System Test .