A/C Inoperative
Thread Starter
Instructor
Joined: Aug 2002
Posts: 198
Likes: 0
From: Yucaipa CA
A/C Inoperative
My A/C quit suddenly. Indicator light on controller is flashing indicating malfunction. Compressor clutch does not engage.
Steps taken so far-
Bypassed pressure switch, no clutch engagement.
Applied 12v to clutch and heard it engage.
Attached gage to low pressure port, started engine and applied 12v to clutch, observed pressure in mid green range.
A/C works with direct application of 12v directly to clutch.
Replaced A/C clutch relay. No joy.
Replaced secondary fan relay. No joy.
Tested for codes, no codes.
It appears that the signal from the control head to the clutch relay is being interrupted.
Please provide any suggestions you may have.
Steps taken so far-
Bypassed pressure switch, no clutch engagement.
Applied 12v to clutch and heard it engage.
Attached gage to low pressure port, started engine and applied 12v to clutch, observed pressure in mid green range.
A/C works with direct application of 12v directly to clutch.
Replaced A/C clutch relay. No joy.
Replaced secondary fan relay. No joy.
Tested for codes, no codes.
It appears that the signal from the control head to the clutch relay is being interrupted.
Please provide any suggestions you may have.
Drifting
Joined: Feb 2016
Posts: 1,384
Likes: 339
From: Simi Valley CA
A couple of the common issues is the AC controller that is above the gas pedal has 2 capacitors that get hot and burn out. That same controller has vacuum lines going through the firewall and those get leaks. Since you say you have working air with the 12v applied directly, I would look at that controller.
