2003 GMC Sierra 1500 Pickup Owner's Manual - Page 177

e (Recirculation): The recirculation mode is used to recirculate the air inside of yourvehicle. Use this mode to help prevent outside odors and/or dust from entering your vehicle or to help cool the air inside of your vehicle more quickly. Press this button to turn the recirculation mode on or off. The light on the recirculation button will illuminate. Recirculation cannot be used in floor, blend or defrost modes. An indicator on the button will light up, flash three times and turn off when recirculation is selected in these modes.Theair-conditioning compressor will also come on when this mode is activated. While in recirculation mode the windows mayfog when the weather is cold and damp. To clear the fog, selecteither the blend or defrostmode and increase fan speed. Temperature Control Driver's Side: The lever on the left side of the climate control panel is used to raise or lowerthe temperature on the driver's side of the vehicle. This lever also adjusts the temperature to the center console outlets (if equipped). 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. Defogging and Defrosting 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 clockwise or counterclockwise to select one of the following modes: This mode directs the air to the floor outlets, windshield and the side window vents. 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. (Defrost): This mode directs most of the air to the windshield and the side window vents, with only a little air directed to the floor vents. The air conditioning compressor will run automatically to dehumidify the air to prevent window fogging. The recirculation mode cannot be selected while in defrost mode. +3 (Defog): 9 a (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 maynotice a slight change in engine performance when the air conditioning compressor shuts off and turns on again. This is normal. 3-22