ASE A7 Heating Air Conditioning Practice Test

A/C Relay Clutch Circuit

24. There is a short to ground at point D of the electrical diagram above. Which of the following statements is correct?

  • A. The clutch would not engage when powered.
  • B. The relay would remain open.
  • C. The PCM would not receive a signal from the clutch.
  • D. The clutch would engage whenever power is supplied to point A.
A/C Relay Clutch Circuit


Answer A is wrong. This circuit is controlled by the PCM. It grounds the relay resulting in compressor engagement.

Answer B is wrong. The relay would remain closed if there is a short to ground before the PCM. It would also likely blow the fuse.

Answer C is wrong. The clutch does not send a signal to the PCM.

Answer D is correct. The clutch would remain engaged when powered.