GMC 2007 Sierra - Manual (Page 243)

Rear Window Defogger
If your vehicle has this feature, 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.
< (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 the vehicle has them.
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.
W (Mirror): If your vehicle does not have a rear
defogger and has 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
better, reducing the chance of fogging
the inside of your windows.
• When you enter a vehicle in cold weather, set
the fan speed to maximum airflow 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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