ASE A7 Heating Air Conditioning Practice Test

Diagram of A/C climate controls.

23. Which of the following statements is correct about component A in the diagram above?

  • A. It is a two-position actuator.
  • B. It is an outside recirculation door.
  • C. It provides feedback to the controller.
  • D. It contains a vacuum motor.
AC temperature blend door circuit diagram.


Answer A is wrong. It's a variable-position actuator. Automatic and semiautomatic air conditioning systems use electric motors that provide real-time feedback on the blend door position.

Answer B is wrong. It's a blend door motor that contains a potentiometer, a type of variable resistor.

Answer C is correct. The controller uses voltage reversal to drive the motor back and forth. It can check the actual position of the blend door with a potentiometer inside the motor assembly.

Answer D is wrong. Automotive air conditioning systems contain different electric door actuators (motors) that blend and distribute air through the duct system and into the passenger compartment. These actuators have replaced or work in unison with vacuum motors and Bowden cables.