GMC Sierra Classic 2007 Owner's Manual page 231

Temperature Control
Driver's Side: The lever on the left side of the
climate control panel is used to raise or lower the
temperature on the driver's side of the vehicle.
This lever also adjusts the temperature to
the center console outlets, if the vehicle has them.
Passenger's Side: The lever on the right side
of the climate control panel is used to raise
or lower the temperature on the passenger's side
of the vehicle.
#
(Air Conditioning): Press this button to turn
the air-conditioning system on or off. When
the button is pressed, an indicator light will come
on and the system will begin to cool and
dehumidify the air inside of your vehicle. You may
notice a slight change in engine performance
when the air conditioning compressor shuts off and
turns on again. This is normal.
Defogging and Defrosting
Fog on the inside of the 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. There are
two modes to choose from to clear fog or frost
from your windshield. Use the defog mode to clear
the windows of fog or moisture and warm the
passengers. Use the defrost mode to remove fog
or frost from the windshield more quickly.
Turn the right knob to select one of the following
modes:
-
(Defog): This mode directs the air to the floor
outlets, windshield and the side window outlets.
The air conditioning compressor will run
automatically to dehumidify the air to prevent
window fogging. The recirculation mode cannot be
selected while in the defog mode.
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