Heated Glass Element: Description and Operation

When the Ignition Switch is turned to "RUN," voltage is applied from the DIC/HVAC Fuse (CKT 541) to the Rear Window Defogger Relay and the Heater-A/C Control. The Rear Window Defogger Relay also receives battery voltage from the R DEFOG Fuse (CKT 1040). When the Reat Defogger Switch is pressed, voltage is momentarily applied to the solid state timer in the Heater-AC Control, sending a ground signal (CKT 193) to the Rear Window Defogger Relay. The solenoid, within the Rear Window Defogger Relay, is energized pulling the switch, within the Rear Window Defogger Relay, closed. When this switch is closed voltage is supplied to the Rear Defogger Grid through CKT 293. The switch will remain closed until the defog cycle is complete or the Rear Defogger Switch is pressed a second time.

When the Ignition Switch is turned to "RUN" and the Rear Defogger Switch pressed for the first time, the defog cycle lasts 10 minutes and further operation will result in 5 minute defog cycles. The defog cycle is reset to 10 minutes when the Ignition Switch is turned to "LOCK" and back to "RUN."

The Defogger "ON" Indicator is an LED that illuminates when the Rear Defogger is "ON." This LED will be step dimmed by the LED Indicator Control when the Park Lamps are turned "ON."