Baffled by ac in 2005 Dodge Durango. Plz help!

[bigjimcfh]

Hi all.
Im new. First post.
I’ve been successful with a/c repairs on other vehicles in the past but this has me stumped. Any help appreciated.
Apologies if a bit long.
I have an issue with ac on 2005 Dodge Durango.

The issue is that ac blows warm air. Have had this Durango for 8 years and this is the first summer we’ve ever had any issues with ac.

Some background. Issue started about a month ago where the front vents would intermittently blow cold air then it would get warm. Typically kicking off the ac by pushing toggle button and back on a few times would be enough to blow cold again. That was until a week or so ago when the air was warm all the time.
The Durango has front and rear ac. I checked pressures and the seemed fine. (L:36ish h:240ish) The clutch engages fine.
I found that the rear was blowing cold air. So immediately i suspected the front expansion valve. I ordered all the parts and tonight I replaced the front expansion valve, accumulator and pressure switch. Figured since I had the system open might as well replace the other stuff. Oiled the new seals and buttoned it all up. Put a vacuum on and it held at 26(lbmurcury??) for an hour or so (while I ate dinner and cooled off in the House). No drop in vacuum, so I charged it all back up. Clutch engages and now NO cold air front or back.
I don’t get it. I feel like I wasted a ton of time. I’m now suspecting compressor but the pressures seem fine and not wacky and clutch engages.
I’m stubborn to a fault some times. I’m on the fence between buying new compressor and testing it or just throwing in the towel and taking to a shop. I’m scared of the prices for the shop and would LOVE to get this working again since it’s our primary family vehicle.

I wondered if anyone would have any thoughts or ideas on what to check or if I should give up and take to a shop. I don’t want to admit defeat just yet, but my family needs cool air.

Any help is appreciated. Thanks in advance!!

[dsar592]

Big Jim,

I have a 2006 Durango, 4x4 with hemi. In the last 4 years I have spent 3300.00 on its a/c system. There aint nothing else to replace. It has worked great for the last year but last week started acting up after a trip to Chattanooga. Funny thing is my pressure readings are pretty good. Anyway I'm taking it to a shop next week. If you want to read all my posts about it, go to Dodgeforum.com and go under the 2nd generation durangos. My username there is bald347. For what its worth, I think the PCM has something to do with it because there are random electrical issues that arrise from time to time like the automatic door locks and unlocks stop working and airbag lights just come on for some reason. Other than the a/c system, the durango has been solid.

[bigjimcfh]

dsar592: Man.. That is a chunk of change to fix the AC. I'm on dodgeforum also. I'll look you up and check out the discussions. Thanks!

[JohnHere]

Some additional food for thought.

As with dsar592, your high pressures seem pretty good. A low side of 36 PSI with a corresponding evaporator temperature of about 42 degrees, even though they are a bit elevated, should still give you some cooling but not at the comfort level we would like. With high pressures in the range you stated, I don't think the compressor is faulty. Otherwise, it wouldn't be able to generate pressures that high.

Could it be the PCM? Yes. But most likely, a malfunctioning PCM would shut off the compressor if the former was acting up. You said that the clutch (and compressor) engage fine. Just curious: Does the compressor run continuously or cycle on and off?

Regardless, all of the foregoing suggests to me some sort of problem elsewhere, not with the PCM.

You said that you pulled a vacuum of 26 inches of mercury (InHg). That's considerably lower than that required to effectively evacuate the system. You need at least 29 InHg pulled for 30 minutes or longer to remove whatever air and moisture might be in the system. Some of one or both contaminants can adversely affect cooling performance.

Could some of the new parts you installed be faulty? Yes. I've seen that more than once. Could it be the Auto Temp Control module in the dash? Sure. A malfunctioning ATC will disrupt the system's functioning as well.