1993 Pontiac Grand Prix Owner's Manual - Page 118

Heating and Ventilation When you don't needto cool the outside air, use these nextsettings. You can leavethe air as it is or heat it. The air conditioner compressor doesn't run in the VNT and HTR settings. This reduces the engine load, resulting in improved fuel economy (gas mileage). VNT (Vent): For mild outside temperatures, when little heating or cooling is needed, push VNT. Air flow is throughthe instrument panel outlets. Slide the temperature control lever a to comfortable level. HTR (Heater): When outside temperatures are cold, push HTR. This will send most the heated air through of the ducts near the floor. Therest will come out of the defroster vents and side window defogger vents. Defogging and Defrosting There are two settings for clearing your windows. For each setting, adjust the temperature control as desired. The air conditioner compressor willrun in these settings to remove moisture from the air when thetemperature is above freezing. This setting allows half of the air to flow to the floor heater ducts, and half to go to the windshield and side window vents located in the windshield pillars. Use this setting to warm passengers while keeping the windshield clear. The setting directs 90% of theair through the defroster vents and the side window vents, and 10% to the floor. \ p