GM Service Manual Online
For 1990-2009 cars only

The heating, cooling, and ventilation for the vehicle can be controlled with this system.

Vehicles Without Air Conditioning


Object Number: 1869165  Size: B1
(Fan): Turn the left knob clockwise or counterclockwise to increase or decrease the fan speed.

Temperature Control: Turn the middle knob clockwise or counterclockwise to increase or decrease the temperature inside the vehicle.

Turn the right knob clockwise or counterclockwise to direct the airflow inside of the vehicle.

To change the current mode, select one of the following:

(Off): Turns the system off.

(Vent): Air is directed to the instrument panel outlets.

(Bi-Level): Air is divided between the instrument panel and floor outlets, with some air directed toward the windshield.

(Floor): Air is directed to the floor outlets with some air directed to the outboard outlets (for the side windows) and to the windshield. The right knob can also be used to select the defrost and defog modes. Information on defogging and defrosting can be found later in this section.

Vehicles With Air Conditioning


Object Number: 1869166  Size: B1

On hot days, open the windows to let hot inside air escape; then close them. This helps to reduce the time needed for the vehicle to cool down and the system operates more efficiently.

(Air Conditioning): This setting will begin to cool and dehumidify the air inside of the vehicle.

(Maximum Air Conditioning): Turn the right knob to for maximum cooling. This setting cools the air the fastest, by recirculating the inside air.

Defogging and Defrosting

Fog on the inside of windows is a result of high humidity (moisture) condensing on the cool window glass. This can be minimized if the climate control is used properly. There are two modes to clear fog or frost from the windshield and side windows.

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 in extremely cold conditions. For best results, clear all snow and ice from the windshield before defrosting.

Turn the knob on the right of the climate control panel to select the defog or defrost mode. The temperature knob should be in the red area and the fan control toward high.

(Defog): Outside air is directed to the floor and defroster outlets. Adjust the temperature knob for warmer or cooler air. The air conditioning compressor may operate in this setting to dehumidify the air.

(Defrost): Most of the air is directed near the windshield, with some going to the floor outlets and front side windows. The air conditioning compressor may operate in this setting to dehumidify the air.

Do not drive the vehicle until all the windows are clear.

Rear Window Defogger

Some vehicles may have a rear window defogger.

(Rear Window Defogger): Press to turn the rear window defogger on or off. Be sure to clear as much snow from the window as possible.

The rear window defogger uses a warming grid to remove fog or frost from the rear window and only works when the ignition is in ON/RUN.

The rear window defogger turns off several minutes after the button is pressed. If turned on again, the defogger will run for several more minutes before turning off. The defogger can also be turned off by pressing the button again or by turning off the engine.

Notice: Do not use a razor blade or sharp object to clear the inside rear window. Do not adhere anything to the defogger grid lines in the rear glass. These actions may damage the rear defogger. Repairs would not be covered by your warranty.