GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 1999 🢒 Aurora 🢒 Body and Accessories 🢒 Stationary Windows 🢒 Defogger System Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

Start the engine.
    • The defogger ON indicator is off.
    • The defogger is off.
    • Go to Defogger Indicator Inoperative
    • Go to Rear Window Defogger Always On

2
  1. Press and release the defogger switch one time.
  2. Wait approximately 11 minutes.
    • The defogger ON indicator comes on.
    • The defoggers come on.
    • After approximately 10 minutes, the defogger ON indicator and the defogger turn off.
    • Go to Defogger Indicator Inoperative
    • Go to Rear Window Defogger Always On

3
  1. Press and release the defogger switch 1 time.
  2. Wait 6 minutes.
    • The defogger ON indicator comes on.
    • The defoggers come on.
    • After 5 minutes, the defogger ON indicator and the defogger turn off.

Go to Rear Window Defogger Inoperative

4
  1. Press and release the defogger switch 1 time.
  2. Wait 15 seconds.
  3. Press and release the defogger switch a second time, before a time-out occurs.
    • The defogger ON indicator comes on.
    • The defoggers come on.
    • When the switch is pressed the second time, both the defogger On indicator and the defoggers turn off immediately.

Go to Rear Window Defogger Inoperative

5
  1. Turn on the radio.
  2. Press and release the defogger switch 1 time.
  3. Wait 15 seconds.
  4. Press and release the defogger switch a second time, before a time-out occurs.

The radio plays normally.

Go to Rear Window Defogger Inoperative

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.