Heated Glass Element: Description and Operation

CIRCUIT OPERATION

With the Ignition Switch in RUN, voltage is applied to the Defogger Control. When the Defogger Control Switch is pressed ON, voltage is applied to the Defogger Timer-Relay. The contacts of the relay close, and provide voltage from the PWR ACC Circuit Breaker (hot at all times) to the ON Indicator and the Defogger. The rear window will become warm to remove condensation from the surface of the window.

The first time the Defogger Control Switch is pushed in, the Timer-Relay will allow the Defogger to operate 10 minutes. Thereafter, each time the Defogger Control Switch is pushed in, the Timer-Relay will allow the Defogger to operate for a maximum of 5 minutes. The Defogger Timer-Relay will reset to 10 minutes when the Ignition Switch is turned OFF and then back to the RUN position.

The timer also shuts off at any time when the Defogger Control OFF Switch is depressed. In order to reset the Defogger Timer-Relay for the initial 10 minute time interval the Ignition Switch must be turned OFF and then back to the RUN position before activating the Defogger.