GM Service Manual Online
For 1990-2009 cars only

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

Vehicles with Air Conditioning shown, without Air Conditioning similar


Object Number: 1505495  Size: B2

Operation

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

(Vent): The air is directed though the instrument panel outlets.

(Bi-Level): The air is split between the instrument panel outlets and the floor outlets. Cooler air is directed to the upper outlets and warmer air to the floor outlets.

(Floor): Most of the air is directed through the floor outlets with some air directed to the windshield and side windows.

The left knob can also be used to select defog or defrost mode. Information on defogging and defrosting can be found later in this section.

(Fan): Turn the center 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 turned on to run the air conditioning compressor.

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

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

(Recirculation): Press this button to prevent outside air and odors from entering the vehicle or to help heat or cool the air inside the vehicle more quickly. An indicator light above the button will come on in this mode. The air conditioning compressor also comes on. This mode is not available for floor, defog and defrost modes. When the recirculation button is pressed, the recirculate indicator light will flash five times and outside air will be delivered. Operation in this mode during periods of high humidity and cool outside temperatures may result in increased window fogging. If window fogging is experienced, select the defrost mode.

Outside Air: This mode allows outside air to circulate through the vehicle. This mode is automatically active if recirculate is not selected. There is no button for outside air.

(Air Conditioning): If your vehicle has air conditioning, press this button to turn the air conditioning system on or off. When this button is pressed, an indicator light above the button comes on to show that the 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 the vehicle to cool down. It also helps the system to operate more efficiently.

For quick cool down on hot days:

  1. Select the mode.
  2. Select the mode.
  3. Select .
  4. Select the coolest temperature.
  5. Select the highest fan speed.

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

The air conditioning system removes moisture from the air, so a small amount of water might drip underneath the vehicle while idling or after turning off the engine. This is normal.

The air conditioning compressor cannot be turned on when the fan is off.

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 the windshield and side windows. When either the defrost or defog mode is selected the system runs the air conditioning compressor.

Turn the left knob to select the defog or defrost mode.

(Defog): Use the defog mode to clear the windows of fog or moisture and warm the passengers. Half of the air is directed to the windshield and side window outlets and the remaining to the floor outlets. To defog the windows faster, turn the temperature control knob clockwise to the warmest setting.

(Defrost): Use the defrost mode to remove fog or frost from the windshield more quickly. Most of the air is directed to the windshield, with some air directed to the side window outlets and the floor outlets. To defrost the windows faster, turn the temperature control knob clockwise to the warmest setting. For best results, clear all snow and ice from the windshield before defrosting.

Rear Window Defogger

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

The rear window defogger will only work when the ignition is in ON/RUN.

(Rear): Press the button to turn the rear window defogger on or off. Be sure to clear as much snow from the rear window as possible. An indicator light above the button comes on to show that the rear window defogger is activated.

The rear window defogger turns off about 15 minutes after the button is pressed. If turned on again, the defogger only runs for about seven minutes before turning off. If the vehicle is moving faster than 50 mph (80 kph), the rear defogger will stay on. 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.