AC works great for months then fails for 2 days , then works months . Twice this has happened. Freon is full . Any ideas ?

 

I had this issue when I was having electrical problems (a dime was loose in the cigarette lighter, and blew up various stuff). The end result, for me anyway, was that the infotainment control was wonky, so the A/C worked fine, but the brains telling it to turn on and off were not doing their job. I have a Ben Hur infotainment conversion, so your mileage may vary, but it sounds to me like your issue is in the infotainment, not in the freon and compressor part. But then again, maybe the controller is sending the right signal but your compressor isn't turning on when told.

I don't know if this helps much, but I know how frustrating it was to have it work, then not work. I have zero idea how to troubleshoot that complex infotainment maybe someone else can chime in.

Of course, the obligatory, "Have your run the ODB codes yet?" If you haven't bought the Ross Tech unit now is the time.

 

Thanks. Its now been out for 3 days so no longer intermittent

 

Have you downloaded the codes yet? If not, buy a Ross Tech and dig in, mystery might be solved

 

Like British said buy a vcds you can buy a copied version from eBay which will do the same for a fraction of the price if all you need is diagnostic.the compressor may have kicked out and won't start again until you clear codes.how do you know gas is full have you just regassed it?

 

I'm currently experiencing the same thing. Everything works as it should but the air is not cold or even cool.

The shop tells me there's a leak although they can't pinpoint it but are willing to replace the compressor and pressure switch for a tad over $3k, then re-evaluate it. How magnanimous of them. This is a shop that does 'foreign' cars, not my 'Bentley' indy, who's scheduled to see the car in 10 days.

Originally i thought it just needed a freon top up & the 'foreign' shop should be able to do so. Nope. They replaced the leaky accumulator, $2k, no difference. On a follow up visit they stated the compressor would only run intermittently. On my own checking, it initially appeared they had overcharged the system, the pressure reading well over 60psi. I released some freon and for a brief minute it blew very cold, then back to warm.

I have a ross-tech scanner, no error codes on the AC. So i'm anxious to see what the actual diagnosis is. There's various sensors in the mix, so i'm hoping its one of them instead of the compressor, but whatever it takes!! the car is basically undrivable in the summer without AC.

 

The shop that did the aircon regas should remove the gas weigh it then adjust the refill accordingly over gassing can have the same effect as not enough. Also they add a dye which under uv light you can see so this will show the area that it is leaking from. Sounds like the garage hasn't got a clue so I would find another garage possibly a vw garage as they will have the vcds software to look at air con system

 

I neglected to post the resolution to my AC issue....replacement of the compressor & related components was required. The accumulator installed by the first shop had to go because the new compressor 'kit' included an accumulator & had to be installed to validate the warranty. The first shop was a 'foreign' service, the second shop was a Bentley specialist.

The AC works fine since the fix, although it's not nearly the ice cold air of the wife's mercedes, I hooked up my auto store recharger to the fixed system just for fun & it still registered way above the 'charged' range, but I'm not touching it!

charlesimps: you said " they explained to me that it is not so severe and it is solved very quickly." what did they tell you & how was it fixed?

 

Hello @LarrysFlyingSpur ,
I have a feeling that @charlesimps may be a spammer, as he is listed as residing in Canada, but post a UK business link for home HVAC, not automotive...

I will remove the link, and most likely Mr.Simps as this is only his second post, and both are of the same manner, spam.

Johnny