1990 Oldsmobile Custom CruiserFACTORY OEM SERVICE PROCEDURE

System Testing

  1. Check fuse. If fuse is okay, go to step 2). If fuse is open, replace fuse. Operate power mirrors. If fuse blows, repair short to ground in power mirror circuit.
  2. Remove mirror switch. Check for voltage on Orange wire at mirror switch connector. If voltage is present, go to step 3). If voltage is not present, repair open condition in Orange wire.
  3. Connect ohmmeter between ground and Black wire at mirror switch connector. If there is continuity, go to step 4). If there is no continuity, repair Black wire between mirror switch and ground.
  4. Test operation of mirror motors. See appropriate table under TESTING in this article MIRROR MOTOR TEST  .
  5. If mirror motors operate in all directions, go to step 7). If mirror motors do not operate in all directions, check for open condition in wiring between mirror switch and mirror motors.
  6. If wiring is okay, replace mirror motor. See, under REMOVAL & INSTALLATION in this article, MIRROR MOTOR  .
  7. Test operation of mirror switch. See appropriate table under DIAGNOSIS & TESTING in this article, MIRROR SWITCH TEST  . If mirror switch fails test, replace mirror switch.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.