GM Service Manual Online
For 1990-2009 cars only

Control Assembly Description C67

Air Conditioning with Electronic Controls (C67)


Object Number: 427393  Size: SH

With the system, you can control heating, cooling and ventilation in the vehicle. The system works best if you keep the windows closed while in operation.

Fan Knob

The left knob selects the force of the air. To turn the fan OFF, turn the knob to OFF. The fan must be on to run the air conditioning compressor.

Temperature Knob

The right knob changes the temperature of the air for the system. Turn this knob towards red to the right for warmer. Turn it towards blue to the left for cooler air.

Mode Push Buttons

The upper row of push buttons control the direction of airflow. For each setting, set the temperature to a comfortable setting. Each button has an indicator which will glow when the button is pressed.

    • VENT: This setting directs the air through the instrument panel outlets.
    • BI-LEVEL: This setting directs air two ways. half the air is directed through the instrument panel outlets. Most of the remaining air is directed through the floor ducts and a little to the defroster and side window vents.
    • FLOOR: This setting sends most of the air through the ducts near the floor. The rest comes out of the defroster and side window vents.
    • DEFOG: This setting allows half of the air to go to the floor ducts and half to the defrost and side window vents.
    • DEFROST: This setting directs most of the air through the defrost and side window vents. Some of the air goes to the floor ducts. The air conditioning compressor will run automatically in this setting unless the outside temperature is below 4.5°C (40°F).

Air Conditioning Compressor Button

Press the A/C button to operate the air conditioning compressor. The indicator light on the button will glow when the button is pressed. You do not have to press the button to run the compressor in DEFOG or DEFROST.

Recirculation Button

This button is used to recirculate much of the air inside the vehicle. This setting is not available in DEFROST.

Outside Air Button

This button is used to bring in outside air.