1997 Pontiac Grand Prix Owner's Manual - Page 168

Heating On cold days use LOWER. The system will bring in outside air, heat it and send it to the floor ducts. If your vehicle has an engine coolant heater, you can use it tohelp your system providewarm air faster when it's cold outside 0°F (- 18O C) or lower. An engine coolant heater warms the coolant your engine and heating system use to provide heat. See "Engine Coolant Heater" in the Index. Ventilation For mild, outside temperatures when little heating or cooling is needed, use UPPER with the A/Cbutton off, to direct outside air through your vehicle. Your vehicle also has the flow-through ventilation system described later in this section. Defogging and Defrosting Your system has two settings for clearing the front and side windows, To defrost thewindows quickly, use DEE To warm passengers while keeping the windows clean, use DEFOG. I' r- Ventilation System Adjust the direction of airflow by moving the louvered vents. Your vehicle's flow-through ventilation system supplies outsid'eair intothe vehicle when it is moving. Outside air will also enter the vehicle when the air conditioning fan is running. 3-8