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Home >> Oldsmobile >> 1990 >> Toronado Base, 4T60/ME9 >> Repair and Diagnosis >> Body & Frame >> Mirrors - Power >> Testing >> System Testing
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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 (check Yellow wire on Corvette). If voltage is present, go to step 3). If voltage is not present, repair open condition in Orange wire (repair Yellow wire on Corvette).
    NOTE: On some Reatta and Riviera models, 2 Black wires terminate at mirror switch connector. One is system ground; other is supply for UP/DOWN motor. To distinguish between Black (Ground) wire and Black (Supply) wire, disconnect mirror switch connector.
    • Connect ohmmeter between vehicle ground and one of 2 Black wires at mirror switch connector. If there is continuity, designate this wire as Black (Ground). If there is no continuity, designate this wire as Black (Supply).
  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 MIRROR MOTOR TEST  table.
  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, MIRROR MOTOR  in this article.
  7. Test operation of mirror switch. See MIRROR SWITCH TEST  table. If mirror switch fails test, replace mirror switch.
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