Operation CHARM: Car repair manuals for everyone.
Hosted by mcallihan.com

Heated Glass Element: Description and Operation


With the Ignition Switch in RUN, the Rear Window Defrost Control is powered through Fuse 5.

Pressing the Rear Window Defrost Switch ON closes the contacts of the Rear Window Defrost Relay and starts the ten minute (approximate) timing cycle. Current then flows to the Rear Window Defrost Grid. When the Rear Window Defrost Control is released from ON, the solid state circuitry keeps the defrost relay coil energized.

Pressing the Rear Window Defrost Control OFF turns off the defrost relay. This removes power from the Rear Window Defrost circuit.

If the OFF switch is not pressed, power will remain on until the time delay runs out. Then the coil will turn off and remove power from the Rear Window Defrost Grid.