GM Service Manual Online
For 1990-2009 cars only

With this system you can control the heating, cooling and ventilation for your vehicle.


Object Number: 808987  Size: B2

Operation

Mode Knob: Turn the right knob clockwise or counterclockwise to direct the airflow inside of your vehicle.

(Vent): This mode directs air to the instrument panel outlets, with a little air directed toward the floor outlets.

(Bi-Level): This mode directs half of the air to the instrument panel outlets, then directs most of the remaining air to the floor outlets. A little air is also directed toward the windshield and the side window outlets. Cooler air is directed to the upper outlets and warmer air to the floor outlets.

(Floor): This mode directs most of the air to the floor outlets with a little air directed to the windshield and the side window outlets.

(Fan): Turn the left knob clockwise or counterclockwise to increase or decrease the fan speed. Turn the mode knob to OFF to turn off the fan.

The mode knob can also be used to select defog or defrost mode. For more information, see "Defogging and Defrosting" later in this section.

On hot days, open the windows to let hot inside air escape; then close them. This helps to reduce the time it takes for your vehicle to cool down. It also helps the system to operate more efficiently.

A/C (Air Conditioning): Turn the knob to the A/C position to turn the air-conditioning system on or off. When the system is on, this setting cools and dehumidifies the air entering your vehicle and directs it through the floor outlets as well as the instrument panel outlets.

MAX A/C (Maximum Air Conditioning): This mode recirculates much of the air inside your vehicle so it cools quickly. It directs most of the air through the instrument panel vents and a small amount through the floor vents.

You may notice a slight change in engine performance when the air-conditioning compressor shuts off and turns on again. This is normal. The system is designed to make adjustments to help with fuel economy while still maintaining the selected temperature.

The air-conditioning system removes moisture from the air, so you may sometimes notice a small amount of water dripping underneath your vehicle while idling or after turning off the engine. This is normal.

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 system is used properly. There are two modes to clear fog or frost from your 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. For best results, clear all snow and ice from the windshield before defrosting.

(Defog): Use this mode to direct half the air to the windshield and half to the floor outlet. Close the center outlets to help defrost the side windows more quickly. In this mode, the system will automatically force outside air into your vehicle and it will also run the air-conditioning compressor, unless it falls below the temperature at which air conditioning is effective.

(Defrost): This mode directs most of the air to the windshield and the side window vents, with only a little air directed to the floor vents. When you select this mode, the system runs the air-conditioning compressor unless the outside temperature is at or below freezing. Do not drive the vehicle until all the windows are clear.

Rear Window Defogger

The rear window defogger uses a warming grid to remove fog from the rear window.

REAR: Press this button to turn the rear window defogger on or off. An indicator light in the button will come on to let your know that the rear window defogger is activated.

If your vehicle has heated outside rearview mirrors, when the rear defogger button is pressed the mirrors will warm to help clear any fog or frost from the surface of the mirrors.

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.