Air conditioning compressor always on

kenb

Member
Original poster
Joined
May 7, 2019
Messages
25
Location
Michigan
Hello,
New member here, I live in southeast Michigan. I have an '05 TJ Sport 4.0 that I purchased last fall,fulfilling my lifelong dream to own a Wrangler. With the spring weather slowly arriving I noticed an issue. It appears that the AC compressor runs constantly regardless of climate control setting. I find that if I remove the relay the compressor clutch disengages. I tried a new relay and no fix. I'm stumped where to look next. Does anyone have suggestions?
Thanks,
Ken
 
About the only time the a/c compressor doesn't run is in the floor/vent settings. The A/C compressor runs in the Defrost and Mix/Bi-Level positions to help keep the windows defogged in addition to the normal A/C and A/C Recirculation settings.
 
Thanks for the reply. It's running even when the system is in the off position (full counter clockwise) and floor / vent.
 
Swap the A/C relay with another and see if the problem goes away.
 
Thanks for the reply. I tried a new relay. Same situation, compressor constantly on with relay installed, off when relay removed.
 
Check the A/C select switch. Might be melted on the backside connector shorting the power to the A/C trigger wire, or just internally shorted.
 
Thanks for the suggestion. Are you referring to the switch located on the dash where the driver selects climate control settings?
 
That switch checked out OK. At this point I'm thinking it's a PCM issue. This is one of the famous auto trans Wranglers with that fault. I had bought a new manufactured pcm for it. I put the original pcm back in and ac works correctly. I have a call in to the manufacturer, pcm is still under warranty, will see what they say.
 
That switch checked out OK. At this point I'm thinking it's a PCM issue. This is one of the famous auto trans Wranglers with that fault. I had bought a new manufactured pcm for it. I put the original pcm back in and ac works correctly. I have a call in to the manufacturer, pcm is still under warranty, will see what they say.

Hello did you work out if it was the pcm? I’m having the exact same issue with a new pcm I have just got.
 
Hello did you work out if it was the pcm? I’m having the exact same issue with a new pcm I have just got.

Yes, it was the PCM. The company that sold me the PCM ended up never returning it when I sent it back to them for warranty repair. They essentially stole my money and my PCM. I got a new PCM from a different supplier and the AC worked normally until I sold that Jeep
 
Yes, it was the PCM. The company that sold me the PCM ended up never returning it when I sent it back to them for warranty repair. They essentially stole my money and my PCM. I got a new PCM from a different supplier and the AC worked normally until I sold that Jeep

I’ve had 2 pcms so far sent to me and both have caused the ac issue. I am getting a third one sent next week. I’m hopeful the issue goes away. Shame that first company screwed you over.
Who was the supplier of the one which worked for you, if you don’t mind me asking? And thanks for the reply