GM Service Manual Online
For 1990-2009 cars only

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


Object Number: 1874983  Size: G3

Operation

The air delivery mode or fan speed can be manually adjusted.

Air Delivery Mode Knob

To change the current air delivery mode, use the left knob to select one of the following:

(Bi-Level): This mode directs air to the instrument panel outlets and to the floor outlets. Cooler air is directed to the upper outlets and warmer air to the floor outlets.

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

(Defog): This mode directs air to the windshield and front door windows. To reduce fogging, press to turn on the air conditioner. The fan must also be on.

(Defog/Floor): This mode directs air to the windshield, front door windows, and floor outlets. To reduce fogging, press to turn on the air conditioner. The fan must also be on.

(Floor): This mode directs most of the air to the floor outlets.

Temperature Control Knob

Turn the center knob clockwise or counterclockwise to increase or decrease the temperature inside the vehicle.

Fan Speed Control Knob

Turn the right knob clockwise or counterclockwise to increase or decrease the fan speed. The speed settings can be adjusted between 1 (Low) and 4 (High).

When the fan is off, the air conditioning compressor is also off. There will be some airflow from the outlets when driving, even with the fan in the off position.

(Fan): Select this position to turn the fan off.

Air Conditioning

For vehicles with air conditioning.

(Air Conditioning): Press to turn the air conditioning system on or off. An indicator light inside the button comes on when the air conditioning is activated. The air conditioning can only be operated if the engine is on and the fan is running. When the air conditioning is on the air is cooled and dehumidified. If cooling or dehumidification is not desired, turn off the air conditioning to save fuel.

On hot days, open the windows briefly to let the hot inside air escape, then close them. This helps to reduce the time it takes for the vehicle to cool down.

For quicker cool down, do the following:

  1. Press to turn on the air conditioning.
  2. Select mode.
  3. Set the temperature knob to the coldest temperature.
  4. Set the fan knob to 4.
  5. Open all vents.

Recirculation

(Recirculation): Press to turn the recirculation mode on or off. An indicator light inside the button comes on when the recirculation mode is active. This mode recirculates air inside the passenger compartment and prevents outside air from entering the vehicle. The quality of the passenger compartment air may decrease since the amount of outside air entering the vehicle is reduced. When the recirculation mode is used without air conditioning, the air humidity increases, and the windows may fog. Avoid using the recirculation mode during high periods of humidity or cool outside temperatures since this may result in increased window fogging. If window fogging is experienced, select the defrost mode.

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 Window Defogger): Press to turn the rear window defogger on or off. An indicator light inside the button will be lit when in use.

If your vehicle has heated mirrors, they turn on when the rear window defogger button is pressed. Press the button again to turn them off. For more information, see Outside Power Mirror(s) .

The rear window defogger will stay on for approximately 15 minutes after the button is pressed, unless the ignition is turned off.

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.