GM Service Manual Online
For 1990-2009 cars only

The heating, cooling, and ventilation for the vehicle can be controlled with these systems.

Vehicles Without Air Conditioning


Object Number: 2051404  Size: B1
  1. Fan Control

  2. Temperature Control

  3. Air Delivery Mode Control

(Off): Turns the system off.

Temperature Control: Turn clockwise or counterclockwise to increase or decrease the temperature.

(Fan): Turn clockwise or counterclockwise to increase or decrease the fan speed. To turn the fan off, turn the air delivery control counterclockwise to the off position.

Air Delivery Mode Control: Turn clockwise or counterclockwise to change the direction of the airflow inside the vehicle.

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

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

(Bi-Level): Air is divided between the instrument panel and floor vents. Cooler air is directed to the upper vents and warmer air to the floor vents.

(Floor): Air is directed to the floor vents. Use this mode to send air to the rear of the vehicle. Keep the area under the front seats free of objects that could obstruct airflow to the rear of the vehicle.

(Defog): This mode clears the windows of fog or moisture. 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): This mode removes fog or frost from the windshield more quickly. Air is directed to 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. The temperature knob should be in the red area and the fan control toward high. Do not drive the vehicle until all the windows are clear.

Vehicles With Air Conditioning


Object Number: 2051405  Size: B1
  1. Fan Control

  2. Temperature Control

  3. Air Delivery Mode Control

  4. Rear Window Defogger

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.

Air Delivery Mode Control: Turn clockwise or counterclockwise to change the direction of the airflow inside the vehicle. Select from the following modes:

(Maximum Air Conditioning): For maximum cooling. The system goes into recirculation mode and helps to maximize the air conditioner's performance and the vehicle's fuel economy. This setting also cools the air the fastest.

(Air Conditioning): For normal cooling on hot days. Outside air is cooled and directed to the instrument panel vents.

(Bi-Level Air Conditioning): Air is divided between the floor and instrument panel vents. The air conditioning compressor cycles continuously in this setting as long as the outside temperature is warm enough to activate the compressor.

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

(Floor): Air is directed to the floor vents. Use this mode to send air to the rear of the vehicle. Keep the area under the front seats free of objects that could obstruct airflow to the rear of the vehicle.

(Defog): This mode clears the windows of fog or moisture. 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): This mode removes fog or frost from the windshield more quickly. Air is directed to 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. The temperature knob should be in the red area and the fan control toward high. Do not drive the vehicle until all the windows are clear.

Rear Window Defogger

For vehicles with a rear window defogger, a warming grid is used to remove fog or frost from the rear window.

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

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

The rear window defogger turns off several minutes after the button is pressed. The defogger can also be turned off 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.