First post on the forum, however I have been on for awhile doing research and learning more about the 3G Acura TLs.

The car is a 2005 Acura TL Auto Non-Navigation with approx. 180k miles on it. Ever since I bought the car two years ago it has had relatively intermittent A/C issues and has only gotten worse. Lately when I start the car the A/C will turn on and run for about ten minutes and then it shuts off and the compressor clutch won't typically engage again until the car has completely cooled off, if I am on the interstate I can get 30 minutes out of it. The condenser fan does stay running even when the compressor shuts off, I haven't measured the vent temps, but before it shuts off it starts to blow out decently cold air (I have ebony interior, so it holds in heat pretty well). I have done some reading on issues similar to mine and most of them point towards the field coil or clutch assembly, however a lot of the posta didn't give a fix to their problem or it is just out dated information, I have only tried swapping relays and it didn't make difference, however I still intend to jump the relay when the car is hot, check for power at the compressor (I don't see this being the issue since it only shuts off when its hot), ohm test the field coil and check the clutch gap.

I was curious if this sounds like a field coil/clutch issue or if I am on the wrong track and should be looking into other things?

 

Last month I think my TL did something similar on my way to Tallahassee. The A/C was on the whole trip and then I noticed the air wasn't blowing out the vents anymore but the A/C was still on, it seems as if the compressor was still working, but the fan/blower wasn't. Later that evening it started back working as normal. I haven't had it checked out yet tho, hoping to find some info on here first.

 

My issue is the compressor shutting off entirely, I still have air coming out of the vents, it just is the same temp as outside without the compressor running. Your issue sounds like it may be a blower motor resistor issue or the blower motor itself, which wiring always being a possibility.

 

If it turns out you need to replace the compressor, rockauto has the OEM part by Denso for around $193 with a new clutch pre-installed.
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There are some elements of your situation that are like what I encountered last year. It ended up being a leak from the AC System Schrader valve. My local non-dealer shop charged me less than $100 to diagnose, replace the valve, and fill the system. It's been working great since. THE DEALER charged me $100 for a diagnosis and wanted $700 to change out the AC components. Thank goodness I got a 2nd opinion. I liken it to having a leak on your home garden hose and someone saying you need to replace the nozzle, hose, and some of your internal plumbing...when all it was, was the nozzle.

 

I came across that when I was searching, however the cost of replacing the entire compressor vs just the field coil and/or clutch is more expensive due to the prices of shops around where I live. They are pricey when it comes to a full evac and recharge.

I know I have a slow leak from my low side schrader valve, but it only leaks when the cap is removed and it has been doing that since day one, plus the air is still cold when the compressor kicks on, I am waiting on my temp gauge to show up so I can check vent temps. I still plan on taking it somewhere to get it checked.

Did some testing this morning:
I jumped the relay this morning when it was 70 degrees outside, with the engine cold the clutch engaged, I am getting 12v at the plug, verified via test light & DMM that attaches to the field coil wiring (I am unable to check it directly at the field coil due to space) and my DMM was reading 4.3-5.0 ohm (about 80 degrees at this point). I drove it around for about thirty minutes enjoying the cold a/c for ten minutes and then drove back home in the heat. I jumped the relay again and got nothing, I checked and I was getting 12v at the plug and I checked the field coil and I was getting infinite ohms both at the plug and at the relay box.

 

You're low on refrigerant. Your schrader valve is not supposed to leak at all and that cap is not going to hold pressure, it's just a cover. Put some soapy water on the valve and confirm leak. Don't run the ac or you risk ruining the compressor running on low refrigerant.

 

I realize the valve isn't suppose to leak (I will also add that the cap has an o-ring in it and physically screws on creating a seal, not saying this will hold up to the pressures in the a/c system), I have intentions of getting it looked at since I can't evac the system myself (legally), sad part is I have a valve that is brand new left over from my other cars a/c refresh, but I am going to have to pay and arm & a leg for a shop to evac it and screw in a new valve & recharge.

I am still trying to resolve a compressor engagement issue, which seems to be caused by my field coil showing an open circuit shortly after the car hits operating temperature. I did check the vent temps this morning and at 70 degrees I am reading 45 degree temps at the vent.

 

Run a wire from the compressor into the cabin, find a ground inside, to check voltage at compressor when driving.
If voltage fine & compressor not operating no clutch engagement another in order, or no voltage at compressor.

 

Before you go electrical engineer on that ish, google search some AC techs to diagnose your refrigerant. Ask them about their process, don't go to one that will simply fill it. The minimum he should using vent thermometers and laser temp gun on the high and low lines.

 

Jerking around with the electric without knowing if refrigerant is up to snuff is definitely not the way to go, but all one needs to do is put gauges on the system, check reading, then start car and check reading again then one would know if it's low. If low, most will be able
to add refrigerant w/o a problem if they know what they are doing just by watching the gauges.

 

I appreciate all of the comments, I will get the appropriate things looked into/at and hopefully can come back to this thread with a solution to my problem.

 

Well I replaced the field coil, clutch assembly & threw in a new relay since they are cheap. A/C works just like it did the day I bought it! Made a 3.5 hour trip with the A/C on the entire time & it didn't skip a beat.