2001 GMC Safari Owner's Manual - Page 163

NOTICE: Don't use a razor blade or something else sharp on the inside of the rear window. If you do, you could cut or damage the defogger and the repairs would not be covered by your warranty. Ventilation System For mild outside temperatures when little heating or cooling is needed, use VENT to direct outside air through your vehicle. Air will flow through the instrument panel vents. Your vehicle's flow-through ventilation system supplies outside air to the inside of your vehicle when it is moving. With the side windows closed, air will flow into the front air inlet grilles at the base of the windshield, through the vehicle and out the rear air exhaust valve. Outside air will also enter the vehicle when the heater or the air conditioning fan is running. Your vehicle has air vents near the center and on the sides of the instrument panel that allow you to adjust the direction and the amount of airflow inside the vehicle. Move the dial on the vent up or down to direct airflow to your preference. Increase or reduce the amount of airflow by opening and closing the louvers. The vents turn to direct the airflow from side to side. 3-7