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Headlight Doors: Testing

  1. Inspect 20-amp HLM fuse. If fuse has failed, go to next step. If fuse is okay, go to step 4).
  2. Replace 20-amp HLM fuse. If fuse fails again, go to next step. If fuse does not fail, go to step 4).
  3. With key off, unplug headlight lift switch, radio, and headlight control module connectors. Unplug main fuse panel connector. Measure resistance between White/Green wire at main fuse panel connector and ground. If resistance is less than 5 ohms, repair the White/Green wire. If resistance is not less than 5 ohms, go to next step.
  4. Reconnect wiring to fuse panel. Measure voltage on White/Green wire at headlight control module. If battery voltage exists, go to next step. If battery voltage does not exist, repair White/Green wire.
  5. With headlights on, measure and record voltage on Red/Black wire at headlight control module. With high beams on, measure and record voltage on Red/White wire at headlight control module. If battery voltage exists on both wires, go to next step. If battery voltage does not exist, repair wire(s) in question.
  6. With ignition off, measure resistance between Black wire at headlight control module and ground. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, repair Black wire.
  7. Measure resistance of Brown, Red, Black, White, and Green wires between headlight control module and left headlight door motor. If resistances are less than 5 ohms, go to next step. If resistance(s) are not less than 5 ohms, repair wire(s) in question.
  8. Measure resistance of Brown, Red, Black, White, and Green wires between headlight control module and right headlight door motor. If resistances are less than 5 ohms, go to next step. If resistance(s) are not less than 5 ohms, repair wire(s) in question.
  9. With headlights off, unplug headlight door motor connectors. Apply 12 volts to Brown wire at headlight door motor connector. Ground Green wire at headlight door motor connector. Headlight door should open. Transpose connections. Door should close. If headlight door opens and closes, go to next step. If headlight door does not open and close, replace headlight door motor(s).
  10. Measure voltage on White/Green wire at headlight lift switch. If battery voltage exists, go to next step. If battery voltage does not exist, repair White/Green wire.
  11. With ignition off, unplug headlight lift switch. Measure resistance of White wire between headlight lift switch and headlight control module. Resistance should be less than 5 ohms. Measure insulation resistance between White wire and ground. Insulation resistance should be more than 10,000 ohms. If resistances are as specified, go to next step. If resistances are not as specified, repair White wire.
  12. With ignition off, disconnect and remove headlight lift switch. With headlight lift switch on, measure resistance between White/Green wire terminal and White wire terminal at headlight lift switch. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, replace headlight lift switch.
  13. With headlight lift switch off, measure resistance between White/Green wire terminal and White wire terminal at headlight lift switch. If resistance is more than 10,000 ohms, go to next step. If resistance is not more than 10,000 ohms, replace headlight lift switch.
  14. Reconnect headlight control module, headlight door motors, and headlight lift switch. Turn headlights on. If headlight doors open, return to TROUBLE SHOOTING and step 1). If headlight doors do not open, replace headlight control module. Turn headlights off. If headlight doors close, return to TROUBLE SHOOTING and step 1). If headlight doors do not close, replace headlight control module.
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