Heated Glass Element: Description and Operation

With the ignition switch in "ON," system voltage is applied through the GAUGE Fuse, the AUDIO ALARM MODULE, and JUNCTION BLOCK 3 to the REAR WINDOW DEFOGGER SWITCH. Battery voltage is applied at all times through the Defogger Circuit Breaker to the Defogger Relay.

Whenever the REAR WINDOW DEFOGGER SWITCH is pressed to the ON position, system voltage is applied through the closed contacts of the switch to the Rear Defogger Indicator and the coil of the Defogger Relay. Since both the Rear Defogger Indicator and the Defogger Relay are permanently grounded, the lamp lights and the relay is energized as soon as system voltage is applied. With the Defogger Relay energized, Battery voltage is applied to the REAR WINDOW DEFOGGER. Because the REAR WINDOW DEFOGGER is a resistive element, it begins to heat as soon as voltage is applied.

The REAR WINDOW DEFOGGER SWITCH does not incorporate an integral timing circuit. Therefore, the switch must be pressed to the OFF position to terminate REAR WINDOW DEFOGGER operation.