Heated Glass Element: Description and Operation

How the Circuit Works

Voltage is applied at all times through fuse 13 to the rear window defogger relay contacts. With the ignition switch in ACC (I) or ON (II), voltage is applied through fuse 16 (in the under-dash fuse/relay box) to the climate control unit/heater control panel and the rear window defogger relay coil.

When you push the rear window defogger switch (in the climate control unit/heater control panel) once, a path to ground is provided for the rear window defogger relay through the climate control unit/heater control panel. The defogger ON indicator in the defogger switch (built into the climate control unit/heater control panel) comes on, and the rear window defogger relay contacts close. Voltage is applied to the defogger grid on the inside surface of the rear window and lower rear window, and the grid heats the glass to remove any fog.

You can turn the defogger off by pushing the rear window defogger switch a second time or by turning the ignition switch to LOCK (O). A timer in the climate control unit/heater control panel will automatically turn the defogger off after it has been on continuously for about 15 minutes.