1995 GMC Jimmy Owner's Manual - Page 136

The upper knob changes the air temperature. Turn the knob clockwise for warmer air. Turn the knob counterclockwise for cooler air. The lower knob selects the heater or air conditioning function and determines which outlets the air will flow through(instrument panel, defroster, heater, etc .) . OFF - This setting turns off all heating functions. Some outside air will still comeout of the heater outlet whenever the vehicle is moving forward. is MAX A/C - Air inside your vehicle recirculated to maximize your air conditioner's performance and your vehicle's economy. This setting fuel cools the air the fastest and should be used to keep "unwanted odors" and/or dust from entering the vehicle. NORM A/C - This setting cools outside air and directs it through the instrument panel vents. This setting is useful for normal cooling on hot days. BI-LEV A/C - Air is delivered through the heaterfloor vents as well as the instrument panel vents. This setting is useful in cool weather with bright sunlight. VENT - Airflow is through the instrument panelvents. Set the upper knob to the temperature desired. This setting is useful for mild outside temperatures, when little heating or cooling is desired. The air conditioner does not run. HEAT - Heated air comes out through the heaterfloor vents and windshield defroster vents. This setting is useful for cold weather. BLEND - Airflow is divided equally between the heater floor vent and the windshield defroster vents. This setting is useful in cool weather when you have fog or ice on the windshield side windows. or DEF - This setting directs most air through the windshielddefroster vents and some through the heater vents. This setting is useful when you have fog or ice on the windshield. Engine Coolant Heater (Option) If you use the optional engine coolant heater before starting your engine, your heating system will produce warmer air faster, to heat the passenger compartment in cold weather. See "Engine Coolant Heater" in the Index. 3-2