GMC 2006 Sierra - Manual (Page 208)

Rear Window Defogger
If your vehicle has this feature, the lines you see on the
rear window warm the glass. The rear window defogger
uses a warming grid to remove fog from the rear window.
If your vehicle has a sliding rear window, you will not
have a rear window defogger; however, your vehicle will
still have a mirror button to activate the heated outside
rearview mirrors, if equipped.
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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. This button will also activate the heated
mirrors, if equipped.
The rear window defogger will automatically turn off
several minutes after the button is pressed. Pressing the
button while the defogger is running can also turn off the
defogger.
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(Mirror): If your vehicle does not have a rear
defogger and is equipped with heated mirrors, your
vehicle will have this button to activate them.
Notice: Do not use a razor blade or sharp object to
clear the inside rear window. Do not adhere anything
to the defogger grid lines in the rear glass. These
actions may damage the rear defogger. Repairs
would not be covered by your warranty.
Outlet Adjustment
Use the air outlets located in the center and on the side
of your instrument panel to direct the airflow.
Operation Tips
• Keep the hood and front air inlets free of ice, snow,
or any other obstruction (such as leaves). The
heater and defroster will work far better, reducing
the chance of fogging the inside of your windows.
• When you enter a vehicle in cold weather, turn the
fan knob all the way to the right for a few moments
before driving. This helps clear the intake ducts of
snow and moisture, and reduces the chance of
fogging the inside of your window.
• Keep the air path under the front seats clear of
objects. This helps air to circulate throughout your
vehicle.
• Adding outside equipment to the front of your
vehicle, such as hood-air deflectors, may affect the
performance of the heating and air conditioning
system. Check with your dealer before adding
equipment to the outside of your vehicle.
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