Heated Glass Element: Description and Operation

Voltage to the Rear Window Defogger Switch is available at all times through the RR DEFOG Fuse S and the ORN (1440) wire. Ground for the Rear Window Defogger Switch is provided through the BLK (150) wire and G102 Engine Ground.

With the Ignition Switch in RUN or START, voltage is available to the Rear Window Defogger Switch through the GAUGES Fuse 4 and the PNK (39) wire.

Turning the Rear Window Defogger Switch to the ON position allows current from the PNK (39) wire to flow through the switch to the Internal Timer Relay. This signal operates the solid-state circuitry in the relay. Current from the PNK (39) wire flows through the relay coil and the relay contacts close. Current from the ORN (1440) wire flows through the relay contacts to the Rear Defogger Grid and G410 through the PPL (293) and the BLK (150) wire. The ON Indicator in the Rear Window Defogger Switch is lit whenever the system is in operation.

After about 10 minutes, the timer in the Internal Timer Relay turns off, opening the relay contacts. Current flow to the Rear Defogger Grid then stops.

The Rear Defogger system can be turned off before the end of the 10 minute timing period by moving the Rear Window Defogger Switch to the OFF position. This turns off the timing circuit and opens the relay contacts.

The Rear Window Defogger Switch is lit with the Headlamp Switch in PARK or HEAD through the GRY (8) wire. Refer to the Instrument Panel Dimming for further information. Lighting and Horns