ncmudbug

I'm having a problem in my '05 C230 where the A/C will shut off at random. I have the dial type A/C controls rather than the digital one. I can get it going again by pressing the AUTO button - sometimes I have to press it for quite a while, other times, I only need to press the AUTO button for a few seconds. The A/C might cut off several times in a day or not at all. It can cut off after driving for 5 minutes from cold. When it works, it works well.

Anybody have any ideas? Does it sound like the control or could it be something else?

Plutoe

Based on you post it sounds as if you have a faulty AC control module. That is based upon you comment that when it works it works well and you have confirmed via gauges that the system is full of refrigerant!!

ncmudbug

That was my assumption, but I was wondering if somebody had a similar experience. I haven't checked the pressures - partly because since it did cool pretty well, I figured they were likely ok - but I'm taking it to the shop for something else and I'll have them check that then.

Thanks!

Icebreaker

When you say the AC works intermittently, do you mean it stops cooling or the fan stops working? Have you tried putting a piece of paper at the slots in the control panel? It should get sucked in if the climate control fan is running.

ncmudbug

Sitting in the car, all I know is cold air stops. The fan stops, but what else stops, I don't know. I suspect that it's only the fan because it starts again after I press the AUTO button (though sometimes it takes a while).

I wondered if there were a defective switch or sensor (and hoped there wasn't), but since it can stop after driving the car for two minutes or 30 minutes or not at all, I figured that it wasn't that the A/C was freezing (isn't there a sensor that detects that the A/C is freezing?).

Icebreaker

The compressor is a variable vane type and will automatically control the pressure by varying the vanes. From what you mentioned it seem to point more to the control module or panel. How many miles do you have on this car? I had the panel go bad the first 6 months I got the car and was replaced under warranty (back in 2006). Apparently the fan that sucks in the ambient air was faulty.

ncmudbug

I have about 106,000 miles on it. I've put two A/C compressors in it the last time was probably about 20 - 25,000 miles ago, maybe a bit more. That one was taken out by the sprag bearing.

My wife has a 2006 C230 and I thought about swapping mine for hers to see if that solved it for me but Mrs. Ncmudbug shouldn't get hot and since it was so intermittent, I didn't know how long it would take to for the problem to come back.

Icebreaker

Sounds like the compressor is OK, maybe the control panel as when you play with the auto switch it comes back on. Have you tried manual control?

ncmudbug

Yeah, that's what I was hoping but wanted to check with people (like you) who knew more about it than I do.

I've seen several different part numbers for A/C controls on ebay. Some come with the trim piece. Some say they are for '06 but not '05. They all look the same to me (all analog like mine and the buttons and the graphic on the buttons is the same). Would you chalk that up to ignorance or a mistake by the vendor in the case of the model year or the inclusion of the trim piece in the case of the part number?

Plutoe

Don't believe the HS over at Ben's Wurld----make sure that you replace the exact same part number of AC control, else you will be back whining.


You do that by posting your VIN and use EPC to correctly advise the AC control part number!!.

insame1

Mine does this also. The only fix I have found is to leave the fan on the first setting then it never turns off.

ncmudbug

So you don't use the AUTO button and just leave the fan on the "1" position? Does that work for you in Austin?

RDVT4ME

I have had this same problem for the 9 years I have owned my 2006. Very random, but mostly when it is really hot, like 90+. It has been to the dealer a couple of times but this issue is not reproducible so they have not been able to find anything wrong. It may do it 5 times today and then not again for a week or more. Pressing the Auto button gets it going again. I will certainly be watching this thread for any possible solution.

insame1

No... I turn on auto and the move the dial up one. Someone here suggested it to me. I don't know why it works but it does.

ncmudbug

Cool (fair choice of words)! I'll give it a try! Thanks!