Heated Glass Element: Description and Operation

Voltage is applied at all times through fuse 38 to the rear window defogger relay. With the ignition switch in ON (II), voltage is applied through fuse 13 to the rear window defogger relay and the defogger ON indicator.

When you turn the rear window defogger switch to ON, a path to ground is provided for the rear window defogger relay and the defogger ON indicator through the integrated control unit. The defogger ON indicator light comes ON and the rear window defogger relay contacts close. Voltage is applied to the defogger grid on the surface of the rear window and the grid heats the rear window to remove any fog from the glass.

A timer in the integrated control unit will automatically turn OFF the defogger after 20 to 30 minutes.