GM Service Manual Online
For 1990-2009 cars only

The optional rear window defogger system consists of a tinted window that has the following components:

    • A number of horizontal ceramic silver compound element lines
    • Two vertical bus bars

These components are baked into the inside surface when the window is formed. The feed wire terminal is soldered to the bus bar on the driver's side. The ground wire terminal is soldered to the bus bar on the passenger side.

The system operates on 12 volts. Under some conditions, heat from the window may not be detected by finger touch. The length of time required to remove interior fog from the rear window will vary with such conditions as the following:

    • Vehicle speed
    • Outside window temperature
    • Atmospheric pressure
    • The number of passengers

This system uses a switch mounted on the instrument panel, and an integral indicator lamp. The system will operate for approximately 10 minutes. Then an automatic timer will turn the system off. If activated for a second time, the system will operate for approximately 5 minutes, then turn off. In order to turn off the system during this operating period, use one of the following methods:

    • Manually turn the switch to OFF
    • Turn off the engine

For system diagnosis, refer to Defogger Schematics or Rear Window Defogger Inoperative .