The mode control is done by cable on your Cavalier. The only a/c system door that has an electric actuator is the inlet door. This switches from outside air to recirculate modes. Max a/c is recirculate, the other modes should all operate on outside air. This actuator is located behind the glove box on the far passenger side of the a/c box. The dash must come out of the vehicle to replace this actuator. These actuators click when the plastic gear inside strips or cracks.
Important: Place the steering column in the straight tilt position using the tilt lever.
Important: Do not tilt the HVAC module assembly, or coolant may leak out.