'07 A/C Not Working

[CherokeeLiberty]

As the title says, my A/C doesn't work. I push the button, and the clutch does not engage. The electric fan does not come on, either. It was like this back in November when I bought it. I pushed the A/C valve with a screw driver and got a hiss, so I'm not worried about a leak. What are some likely causes? Is it possible to test any sensors?

 

[LibertyTC]

The system will protect itself if low, and not meeting or within specifications.
Best to have an AC specialist hook up the high / low gauges and see where it is at.
Based on temp here are the required high low specs..

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[ltd02]

Yeah, it could have some Freon but not enough. Best to have it check by a professional. You can jumper the low pressure switch with a decent gauge wire and see if the compressor kick on but only briefly so as not to damage it by running too long without refrigerant.

 

[CherokeeLiberty]

Thanks. I know I'll need to get it into a shop for some diagnostics, but I just wanted to know if there was anything I could do until then.

What are some common issues with a KJ's A/C system?

 

[ltd02]

I couldn't say. I've had an 02 from 2007 until 2016 and an 05 from 2016 til now and I've never had an issue with the air in either. Never even had to top off the refrigerant. I'd have to say they're the coldest AC in my fleet of 6 vehicles.

 

[Birdman330]

Look at the HVAC control system, they're known to short out. Had a similar issue, where it was working then suddenly quit on me driving home. Push the button, it would light up but the AC would not work. Checked the R134A Levels they were fine, thought it was one of the pressure switches, they were fine. Tested the HVAC AC Power button, there was the problem.

 

[CherokeeLiberty]

Look at the HVAC control system, they're known to short out. Had a similar issue, where it was working then suddenly quit on me driving home. Push the button, it would light up but the AC would not work. Checked the R134A Levels they were fine, thought it was one of the pressure switches, they were fine. Tested the HVAC AC Power button, there was the problem.

How did you end up fixing that? Was it just the button that was bad?

 

[Birdman330]

You have to replace the unit, rather simple to do takes about 20 minutes. Yes it was the button that was bad, had shorted out.

 

[CherokeeLiberty]

You have to replace the unit, rather simple to do takes about 20 minutes. Yes it was the button that was bad, had shorted out.

Where did you find a replacement?

 

[Birdman330]

I order my Jeep replacement parts from factory chrysler parts, which is run by a Chrysler Dealership in Florida. http://www.factorychryslerparts.com

 

[CherokeeLiberty]

I did some troubleshooting tonight.

First, I swapped the A/C relay for the wiper relay. No change. I tested the connections with the A/C button on and off.

Then, I grabbed my meter. There was no power to the relay on the side with three small posts (the middle one doesn't seem to have a connector to use). One of the bigger two has 14V at idle.

I started probing other switches and sensors after this. Here is what I found:

The connector on the compressor had no power.

The low pressure switch had 14V across it, though I need to retest this. I tried back probing the connector, but the probes were not long enough. So, I pulled the connector and tested across and got 14V. I imagine this will always have power. I will check the switch itself tomorrow.

I tested the high pressure switch, but I forget what I came up with. It's been a long day. I'll check this tomorrow.

The big test tomorrow will be the HVAC control unit. I'll pop it out and see if that button is doing it's job. The light lights up, but I doubt that means anything other than a good circuit for the LED.

I'll also look for a set of HVAC gauges at work tomorrow. I'd like to know what it going on inside the system.

 

[Birdman330]

Let's just say I blew out my basic light test meter to figure out it was the button.

 

[CherokeeLiberty]

I don't think I even have a light tester.

I haven't been able to get back at it. It's been storming, and now we're packing up for a weekend camping trip. We're taking the GF's Mariner which has great A/C

 

[uss2defiant]

i suppose you can pick up a loaner A/C gauge from autozone and look at the pressures.