GM Service Manual Online
For 1990-2009 cars only

Your vehicle may have a manual climate control system. With this system you can control the heating, cooling and ventilation for your vehicle.


Object Number: 1202421  Size: B2
(Fan): Turn the left knob clockwise or counterclockwise to increase or decrease the fan speed. In any setting other than off, the fan will run continuously with the ignition on. The fan must be on in order for the air conditioning compressor to run.

0 (Off): To turn the fan off, turn the knob all the way counterclockwise to the off position.

TEMP (Temperature): Turn the middle knob clockwise or counterclockwise to manually increase or decrease the temperature inside your vehicle. Turn the knob to the blue area to get cool air and to the red area to get warm air.

To change the current mode, select one of the following from the right knob:

(Vent): This mode directs air to the instrument panel outlets.

(Bi-Level): This mode directs about half of the air to the instrument panel outlets, and then directs the remaining air to the floor outlets.

(Floor): This mode directs most of the air to the floor outlets. If your vehicle has rear outlets, some of the air will also be directed to them. Be sure to keep the area under the front seats clear to allow the flow of air to the rear compartment. The right knob can also be used to select the defog and defrost modes. Information on defogging and defrosting can be found later in this section.

(Recirculation): This mode keeps outside air from coming in the vehicle. It can be used to prevent outside air and odors from entering your vehicle or to help heat or cool the air inside your vehicle more quickly. Press this button to turn the recirculation mode on or off. When the button is pressed, an indicator light in the button will come on. Using the recirculation mode for extended periods may cause your windows to fog. If this happens, select the defrost mode.

A/C (Air Conditioning): Press this button to turn the air conditioning compressor on and off. When A/C is pressed, an indicator light in the button will come on to let you know that air conditioning is activated.

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.

For quick cool down on hot days, do the following:

  1. Select the vent mode.
  2. Select the highest fan speed.
  3. Press the A/C button.
  4. Select the recirculation mode.
  5. Select the coolest temperature.

Using these settings together for long periods of time may cause the air inside of your vehicle to become too dry. To prevent this from happening, after the air in your vehicle has cooled, turn the recirculation mode off.

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 or 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. 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.

Select one of these available modes from the right knob.

(Defog): This mode directs most of the air to the windshield and the floor outlets. A small amount of air is also directed to the outboard outlets for the side windows and to the instrument panel side outlets. When you select this mode, the system runs the air-conditioning compressor. To defog the windows faster, turn the temperature control knob clockwise to the warmest setting.

(Defrost): This mode directs most of the air to the windshield and the outboard outlets for the side windows. A small amount of air is also directed to the instrument panel side outlets. When you select this mode, the system runs the air-conditioning compressor. To defrost the windows faster, turn the temperature control knob clockwise to the warmest setting.

Do not drive the vehicle until all windows are clear.

Rear Window and Outside Mirror Defogger

Your vehicle has a rear window and outside mirror defogger. This feature will only work when the ignition is turned to ON.

The rear window defogger uses a warming grid to remove fog or frost from the rear window. Before using this feature, clear as much snow from the rear window as possible.

(Rear): Press this button to turn the rear window and outside mirror defogger on or off. The button is located below the audio system. An indicator light in the button will come on to let your know that the feature is activated.

The rear window and outside mirror defogger will turn off about 10 minutes after the button is pressed. The defogger can also be turned off by pressing the button again or by turning off the engine.

Notice: Do not use anything sharp on the inside of the rear window. If you do, you could cut or damage the warming grid, and the repairs would not be covered by the vehicle warranty. Do not attach a temporary vehicle license, tape, a decal or anything similar to the defogger grid.

Front Heated Windshield

Your vehicle may have a heated front windshield which can be used to defrost it. This feature will only work when the ignition is turned to ON.

There is a heated element along the bottom of the windshield used to heat the windshield.

(Rear): Press this button to heat the windshield. The button is located below the audio system. An indicator light in the button will come on to let your know that the feature is activated.

The front windshield heater will turn off about 10 minutes after the button is pressed. It can also be turned off by pressing the button again or by turning off the engine.