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 baked into the inside surface during the glass-forming operation:

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

The feed wire or terminal is soldered to the bus bar on the left side. The ground wire or terminal is soldered to the bus bar on the right side.

The system operates on 12 volts. Under some conditions, heat from the window may not be detected by finger touch. This system uses an instrument panel-mounted switch with an integral indicator lamp that operates for 5-10 minute cycles. The indicator lamp turns off through the use of an automatic timer. The rear window defogger switch may need to be pressed for additional cycles depending on the following conditions:

    • Vehicle speed
    • Outside window temperature
    • Atmospheric pressure
    • Number of passengers

Turn off the system during this operation period by turning either the instrument panel-mounted switch or the ignition switch to the OFF position.