A/C compressor not engaging...

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Apr 9, 2013 | 10:41 PM

bingo1105

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From: San Antonio Texas

A/C compressor not engaging...

It's getting warmer and I've noticed that the A/C on my '05 is no longer working. The compressor is not engaging, and I've checked what I can. The belt is good, the relay is good, the fuse appears good from a visual inspection (although I guess I could swap it), the static pressure on the low side pegs my cheapo tool to 80+ PSI with the car off (that's the max it will read), so I assume there is enough freon in the system to at least cycle the compressor. Any thoughts on what I should be looking for?

Thanks for any guidance you can offer...

Edit: Could be unrelated, but I occasionally get a 'service charging system' fault on the DIC. It happens rarely, but is there a ground I should be checking??

Last edited by bingo1105; Apr 9, 2013 at 11:00 PM.

Apr 10, 2013 | 04:19 PM

TCW

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Joined: Jan 2001

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From: Maryville TN

St. Jude Donor '06-13,'16-'17, '19

If the A/C relay isn't clicking on and off, then the electronic clutch on the compressor isn't being engaged at all.

If this is the case I'd look at the interior temp sensor. It sounds like the system isn't asking for the AC to come on.

Tom

Apr 10, 2013 | 07:52 PM

bingo1105

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From: San Antonio Texas

Quote:

Originally Posted by TCW

Thanks for the reply. The relay is not clicking, even when I set it to defrost. I'll check the sensor and see if that helps...

Apr 10, 2013 | 09:27 PM

truckplay

Melting Slicks

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From: Sugarhill Ga

I had that happen the other day

I never shut off the ac in any car, top on or off. The other day I noticed my a/c not cooling also. I had just gotten back from the track and noticed that it had been on the whole time. I wondered if I had damaged the clutch but asking it to repeatedly spin at 6k all night. When I first tried engaging the ac, it just made noise, GREAT I thought, but after pressing the on/off a few times it started working normal and has for a few days KNOCK ON WOOD.

good luck

Apr 10, 2013 | 10:17 PM

bingo1105

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Well, it turns out I'm a dumbass. It was the belt after all... it appeared to be in place when I looked under the hood but it wasn't turning at idle. Must have been thrown at high RPM... I will replace and that should take care of things...

Is the tensioner adjustable? Or is a new belt all I need?

Apr 11, 2013 | 08:08 AM

truckplay

Melting Slicks

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From: Sugarhill Ga

the belt fell off ?
the tentioner is not adjustable, while the belt is off, spin the clutch on the compressor then install the belt and press down on the belt feeling for tension, then start the engine and watch ALL the pulleys especially the harmonic balancer, something may not be spinning true.

Apr 11, 2013 | 11:58 AM

cclive

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From: Southern Utah

The belt falling off is something that needs investigation. It is a very short belt that should run true. It does not run lots of things like the main belt does, so it should have a much lower risk of falling off the pulleys.

Apr 11, 2013 | 07:10 PM

bingo1105

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From: San Antonio Texas

Quote:

Originally Posted by cclive

Agreed. I replaced the belt and everything is working and appears to be running true. The car has a 25% underdrive pulley and the belt length is 39.5 inches, which seems correct. The car gets run on the track so maybe it's the combination of pulley and high RPM's? I'll keep an eye on it and welcome any further comments...