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 feedback on the blend doors position in real-time.

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's able to check the actual position of the blend door with a potentiometer located 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.