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Circuit/System Testing - Dual Generators

  1. Verify that a test lamp illuminates between the each generator B+ terminal 1 X2 or A X2 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Ignition OFF.
    2. Test for less than 2 Ω in each B+ circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Ignition OFF.
    2. Test for greater than 100 Ω between the B+ circuit and ground.
      • If 100 Ω or less, repair the short to ground on the circuit.
      • If greater than 100 Ω, replace the appropriate generator.
    • Go to next step: If the test lamp illuminates 
  2. Ignition OFF, disconnect the X1 harness connector at the Generator - Primary and Generator - Auxiliary, engine running.
  3. Test for 3.0 - 5.5 V between the control circuit terminal 1 X1 and ground.
    • If less than 3.0 V 
    1. Ignition OFF, disconnect the harness connectors at the ECM.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the control circuit end to end.
      • If greater the 2 Ω, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the ECM.
    • If greater than 5.5 V 
  4. Ignition OFF, disconnect the harness connectors at the ECM, Ignition ON.
  5. Test for less than 1 V between the control circuit and ground.
    • If 1 V or greater 

      Repair the short to voltage on the circuit.

    • Go to next step: If less than 1 V 
  6. Ignition OFF, connect X1 harness connector at the Generator - Auxiliary, Ignition ON.
  7. Test for less than 1 V between the control circuit and ground.
    • If greater than 1 V 

      Replace the Generator - Auxiliary.

    • Go to next step: If less than 1 V 
  8. Ignition OFF, connect X1 harness connector at the Generator - Primary, Ignition ON.
  9. Test for less than 1 V between the control circuit and ground.
    • If greater than 1 V 

      Replace the Generator - Primary.

    • Go to next step: If less than 1 V 
  10. Test or replace the ECM.
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