Circuit/System Testing

LY7 Engine

1. Verify that a test lamp illuminates between the G13 generator B+ terminal + X2 and ground.
   • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
2. Ignition OFF, disconnect the harness connector at the generator.
3. Ignition ON, test for less than 1 V between the control circuit terminal 1 and ground.
   • If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
4. Engine running, test for greater than 3.5 V between the control circuit terminal 1 and ground.
   • If less than the specified range, test the control circuit for a short to ground, an open or a high resistance. If the circuit tests normal, replace the K20 ECM.
5. If the circuit tests normal, test or replace the G13 generator.

LE5, LZ4 or LZ9 Engine

1. Verify that a test lamp illuminates between the G13 generator B+ terminal + X2 and ground.
   • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
2. Ignition OFF, disconnect the harness connector at the generator.
3. Ignition ON, test for 4.5-5.5 V between the control circuit terminals listed below and ground:
   • Terminal 1 (LE5)
   • Terminal B (LZ4, LZ9)
   • If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
   • If less than the specified range, test the control circuit for a short to ground, an open or a high resistance. If the circuit tests normal, replace the K20 ECM.
4. If the circuit tests normal, test or replace the G13 generator.