Heated Glass Element Switch: Description and Operation

The heated back window defroster system consists of:
- Generic Electronic Module (GEM)
- switch mounted on the instrument panel
- a series of grid lines baked on the inside surface of the rear window and system wiring. The grid lines consist of two layers.

The switch has a push button, spring-loaded to neutral position, to turn the system on or off, and a generic electronic module-controlled relay that turns off automatically after approximately 10 minutes of operation. If more than 10 minutes is required, the control can be reactivated for another 10 minutes by pushing the button momentarily to the ON position. This operation can be repeated as required.

When the switch is pushed to the ON position with the ignition switch in RUN, the normally open contacts in the relay are electrically closed, thus providing power from battery to the heated rear window grids, the indicator and the heated outside rear view mirror (if equipped). These contacts will remain closed until the generic electronic module turns them off, or the switch is pushed momentarily to the OFF position, or the ignition switch is turned to the OFF or ACC position.