Heated Glass Element: Description and Operation

OPERATION
With the Ignition Switch in "START" or "RUN", voltage is present at the Rear Window Defrost Switch through the DEFOG Fuse.

Pressing the Rear Window Defrost Switch closes contacts inside the switch. Current flows through the DEFOG Fuse, the Rear Window Defrost Switch, the I/P Fuse Panel, and the Rear Window Defrost Grid to ground. Current also flows through an ON Indicator Bulb, located inside the Rear Window Defrost Switch, to illuminate the bulb.

A "defroster on" signal is also supplied to the Powertrain Control Module (PCM) when the Rear Window Defrost Switch contacts are closed.

Pressing the Rear Window Defrost Switch again opens the switch contacts, interrupts current flow to the Rear Window Defrost Grid, and turns off the system.

The Rear Window Defrost Switch must be turned off to turn off the system.

NOTE: This vehicle does NOT use a Rear Window Defrost Switch timer to turn off the system after a specific period of time. Also, the system will NOT cycle off when the Ignition Switch is turned to LOCK; as soon as the Ignition Switch is turned to RUN again, the system will turn on again.