2005 Buick Rendezvous Owner's Manual - Page 170

Defogging and Defrosting Fog on the inside of windows is a result of high humidity, or moisture, condensing on the cool window glass. This can be minimized if the climate controls system is used properly. 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 right knob to select the defog or defrost mode. Rear Window Defogger The rear window defogger uses a warming grid to remove fog from the rear window. < 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. The rear window defogger will turn off approximately 10 minutes after the button is pressed. If turned on again, the defogger will only run for approximately five minutes before turning off. The defogger can also be turned off by pressing the button again or by turning off the engine. Notice: Don't use anything sharp on the inside of the rear window. If you do, you could cut or damage the warming grid, and the repairs wouldn't be covered by your warranty. Do not attach a temporary vehicle license, tape, a decal or anything similar to the defogger grid. - (Defog): This mode directs air to 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. 0 (Defrost): This mode 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. Do not drive the vehicle until all the windows are clear. 3-32