Actuator, Blend Door: Operation: Operation

WARNING: This page is about a different car, the 2015 Fiat 500. However, it is still accessible from the selected car via links, so may be relevant.

The blend door actuator used in the Automatic Temperature Control (ATC) heating and A/C system is connected to the A/C heater control by a dedicated five-wire lead and connector of the HVAC wire harness. The blend door actuator can move the blend-air doors in two directions. When the A/C heater control pulls the voltage on one side of the motor connection high and the other connection low, the blend door actuator will move in one direction. When the A/C heater control reverses the polarity of the voltage to the motor, the blend door actuator moves in the opposite direction. Once the A/C heater control makes the voltage to both connections high or both connections low, the blend door actuator stops and will not move.

The blend door actuator contains a potentiometer, which the ATC A/C heater control uses to monitor the relative position of the blend-air doors. The A/C heater control learns the blend-air door stop positions during the calibration procedure and will store a diagnostic trouble code (DTC) for any problems it detects in the blend door actuator circuits. Refer to DIAGNOSIS AND TESTING .

The blend door actuator cannot be adjusted or repaired and must be replaced if inoperative or damaged.