Defogging And Defrosting; Outlet Adjustment - GMC 2003 GMT560 T-Series Owner's Manual

Defogging and Defrosting

There are two modes 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 center knob to select the
defog or defrost mode.
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(Defog): This mode directs the air equally between
the windshield and the floor outlets. When you select
this mode, the system turns off recirculation and runs the
air-conditioning compressor unless the outside
temperature is at or below freezing. The recirculation
mode cannot be selected while in the defog mode.
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(Defrost): Pressing this button directs most of the
air to the windshield and the side window outlets,
with some air directed to the floor outlets. In this mode,
the system will automatically turn off recirculation
and run the air-conditioning compressor, unless the
outside temperature is at or below freezing.
Recirculation cannot be selected while in the
defrost mode.

Outlet Adjustment

The air outlets are located in the center and on the
sides of your instrument panel. You can move the vents
to direct the flow of air or close the outlets altogether.
When you close a vent, it will increase the flow of
air coming out of any vents that are open.
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