Rear Window Defogger - GMC Envoy Owner's Manual

Defogging and Defrosting
Fog on the inside of windows is a result of high humidity
(moisture) condensing on the cool window glass. This
can be minimized if the climate control system is
used properly. You can use either defog or front defrost
to clear fog or frost from your windshield.
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(Defog): Use this setting to clear the windows of fog
or moisture. This setting will deliver air to the floor
and windshield outlets.
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(Defrost): Press the front defrost button to clear
the windshield and side windows of frost or fog quickly.
The system will automatically control the fan speed if
you select defrost from AUTO mode. If the outside
temperature is 40°F (4°C) or warmer, your air
conditioning compressor will automatically run to help
dehumidify the air and dry the windshield. Do not
drive the vehicle until all the windows are clear.

Rear Window Defogger

The rear window defogger uses a warming grid to
remove fog from the rear window.
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(Rear): Press this button to turn the rear window
defogger on or off.
An indicator light in the button will come on to let you
know that the rear window defogger is activated.
The rear window defogger will turn off approximately
10 minutes after the button is pressed. If you need
additional warming time, press the button again.
If equipped, your heated mirrors will also come on when
you press this button.
Notice: Using a razor blade or sharp object to clear
the inside rear window may damage the rear
window defogger. Repairs would not be covered by
your warranty. Do not clear the inside of the rear
window with sharp objects.
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