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scottunzicker 04-29-2011 05:47 PM

Air Conditioning Troubleshooting
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First of all, thanks for everyone's input in re: to my "master plan" of upgrades. They were all really helpful, and I'm well on my way!

Here's the scoop -

On a recent trip from Austin to Denton, my A/C cut out. It was blowing plenty cold when I switched it over to vent for some power (it's a 4 banger, and I was going uphill ;) ). When I switched it back to A/C mode maybe 15 minutes later, the air temp didn't get cold.

What it DOES do is drop the engine RPM a little bit like it used to when it worked. So, at idle, I can have the vent (fan) blowing just fine. When I switch it over to A/C, the idle RPMs drop a little (like it always used to), but the air doesn't get cold.

What I've tried so far:

Coolant check - My stepdad works on A/Cs for a living, and the coolant pressure level tested fine.

Compressor check - Not sure if what we did was ok, but tried putting 12v across it to see if we could hear the clutch engaging. Never did.

Switch removal - I removed the switch in the dash and Deoxd the daylights out of it... that's when I noticed that the bottom of the switch looks pretty blistered (see below). I hooked it back up, tested it, and both it, and the thick black wire that's connected (there are three wires: one green and two black) are getting really really hot.

So where do I go from here? I've got a multimeter and can sort of use it. Any and all troubleshooting steps are greatly appreciated!

ALSO - Does anybody know what size bolt attaches the stabilizer bar link to the tie rods, etc.?

deathphoenix99 04-29-2011 07:19 PM

It looks like you need a new switch first off, and if the clutch wasn't engaging when you had it directly powered, then you may have a bad clutch, which "could" explain why the switch was overheating.

scottunzicker 04-29-2011 07:47 PM

Thanks for the reply! Like I mentioned in the post, even now with just the fan (vent) selected, the switch and one of the wires get REALLY hot. As in, I can't touch it for more than a second.

What's a smart way of testing the clutch on the compressor?

Thanks again!


Originally Posted by deathphoenix99 (Post 1210356)
It looks like you need a new switch first off, and if the clutch wasn't engaging when you had it directly powered, then you may have a bad clutch, which "could" explain why the switch was overheating.

rrich 04-29-2011 08:04 PM

"""""What's a smart way of testing the clutch on the compressor?"""""

Open the connector at the clutch.
One wire - apply 12 volts to it.
Two wires - one gets 12 volts, the other gets grounded.
Polarity doesn't matter as long as the connector is disconnected.
Clutch should engage.

scottunzicker 04-30-2011 06:27 PM

Howdy - I was able to successfully test the compressor clutch. I put 12V across it, and got a good click. I started the jeep, and "manually" engaged the compressor, and sure enough, the A/C blew good and cold. Glad it's not that.

So NOW what? Replace the switch, obviously (can anybody recommend a good source for one?), but what's making it heat up so badly?

Thanks again for the help, y'all!


rrich 04-30-2011 06:48 PM


shipjim 04-30-2011 09:31 PM

I have a similar problem, have had it "fixed many times" If I knew in advance I'd never had put any money in it now I'm stuck making it work. Try again monday. jj

dmcg 04-30-2011 10:51 PM

Ditch the A/C, its a Jeep. You will get better gas mileage and more horsepower. I've never once turned mine on in Texas

deathphoenix99 04-30-2011 11:18 PM

If the clutch engages manually, then it's not bad. The switch could be the reason the a/c won't engage as well. But first, check the low pressure switch, verify that it is in closed position, because if it's "open" then that means that the system is low on refrigerant.

To test, locate low pressure switch, remove connector and use a continuity test or voltmeter to verift that the circuit is closed and you can get current accross the pins.

scottunzicker 05-01-2011 03:40 AM

Deathphoenix99 - Thanks for the next step! I'll most likely give it a go tomorrow. @DMCG - Man, I understand where you're coming from. However, there are certain females in my life who prefer the A/C. Plus, I don't really mind spending the time under the hood, getting to know everything better. I drove a 2000 VW GTi VR6 for the last 10 years, and everything is so computerized and condensed, that a normal dude like myself had no chance at making anything work (for the record, my car before THAT was a 1991 Honda CRX Si - GREAT car, and you could do a lot with it! Before THAT a '63 1/2 VW Bug). Hence, I enjoy the challenge of the troubleshooting process.

Again, does anybody know the size of the bolt attaching the stabilizer bar link to the tie rods?

Thanks, everyone!!!

shipjim 05-04-2011 06:43 PM

It's now Wednesday, A/C still isn't fixed. Now there's a "leak" Hell's bells, wish I'd never started fooling with it, it's a nice to have in Houston but I do have another vehicle, and i bought it for Colorado's mountians. I'm in $600, $100 at a time!

deathphoenix99 05-04-2011 08:22 PM

^Do you know where it's leaking? What have you done to it and what have you not done to it? I can try to help you as well.

shipjim 05-06-2011 08:08 PM

Thanks Death,
It turned out that there was corrosion on the switch link under the hood. After much testing, giggling etc it was replaced and the connection held. jj

deathphoenix99 05-07-2011 04:07 PM

Glad it's fixed.

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