Heated Glass Element: Description and Operation

Voltage is applied at all times through fuse 50 to the rear window defogger relay (contacts). With the ignition switch in ON (II), voltage is applied through fuse 16 to the rear window defogger switch.

When you turn the switch ON, voltage is applied to the defogger timer circuit. The timer circuit supplies voltage to the rear window defogger relay (coil). The relay energizes and supplies voltage to the rear window defogger. The defogger grid then heats the rear window to remove any condensation from the glass.

The defogger timer circuit will automatically turn off the rear window defogger after about 25 minutes.