GM Service Manual Online
For 1990-2009 cars only

The optional rear window defogger system consists of a tinted window that has a number of horizontal ceramic silver compound element lines and two vertical bus bars baked into the inside surface during the glass forming operation. 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. The length of time required to remove interior fog from the rear window will vary with such conditions as vehicle speed, outside window temperature, atmospheric pressure and the number of passengers. This system uses an instrument panel mounted switch with an integral indicator lamp that will operate for five to ten minutes and then automatically turn off through the use of an automatic timer. The system can be turned off during this operation period by turning off either the instrument panel mounted defogger switch or by turning off the ignition switch.