You should pull the codes and report back. Do a search on here for the methods and the meanings of the codes. It could be one of your sensors, low refrig., bad or out of code CCU, etc., etc. Michael

 

Thanks for the QUICK reply, Michael. If I was able I would, but I have no equipment to do such tests. This area is a desert compared to Mojave...we only have 3 shops that are even the least bit trustworthy...and my "friend" is the best of the pick. If you think that's bad, we could talk about the dearth in Porsche mechanics! :-(

 

I'm having the same problem -- the A/C compressor clutch does not turn on. So far, I have checked all fuses, relays. I also checked the low pressure switch, but no banana. Right now I'm betting that it might be the CCU (manual unit), because the blower fan operation is screwey. Other things left to check are the temp swithches on the engine and on the evaporator.

I'll keep you posted on my progress.

If your CCU is digital, than you can pull diagrnostic codes.

 

I'm having the same problem -- the A/C compressor clutch does not turn on. <snip>
If your CCU is digital, than you can pull diagnostic codes.

I notice last night that an old problem has returned. The bloody EC light is always on and won't turn off. This indicates the compressor is turned off for winter conditions...the outside temp was 50 F! Sounds as if we have similar problems, eh.

 

Unfortunately I don't have the digital CCU. The EC light is working OK, but the compressor clutch does not engage. I'm getting a replacement ccu because the blower fan operation is screwey (clicking noise coming from the blower when the ccu fan switch is in the OFF position, and erratic fan operation in the ON positions. So, I'm hoping that the ccu is the problem.

I'm also looking at purchasing the Bentley C-Class Maintenance/ Service manual. Trying to diagnose this A/C problem without a manual is like shooting in the dark, or throwing mud at the wall to see what sticks. I figure it will be money well spent.

Looking into Mercedes A/C problems, I find that the failure rate is quite high, with mega buck repair bills. Two of my co-workers recently spent Approx. $1600 each to have their Mercede A/C systems fixed. The problem areas seem to be with the compressors and electrical components. There are many complaints of customers being ripped off by having the entire system replaced when the fix only required a small/cheap component.

 

Don, do you have a manual unit too? If you have a digital display unit, you can check your codes without tools. Here is how to reset your DIGITAL unit: http://glenet.net/mercedes/W202 VERSION CODE.pdf. Also, to pull your codes, you need to hold down the rest button for 5 seconds. On the early CCU, you cycle through them with the arrow up (windshield) arrow down (floor). Maybe someone can weigh in on the later digital CCU's for cycling information. Then, post your results if you have a digital unit.

 

Thank you Metafly. I have a digital unit as shown in the PDF; which is almost self explanatory...only one problem. What/where is the RESET switch. I assume it isn't the odo reset, or again is it foolish to assume again? ;-)

 

Dear Don:

I think you mean the "Rest" button on your actual CCU.

 

Found the problem...frozen AC unit. Tried to turn it with wrench and couldn't. Found on eBay for $300.

 

How can I include an icon that shows embarrassed? For Firefox it would be :-[ I never remember that the RESIDUAL HEATING button. Thanks again!

Please post your results:thumbsup:

 

Your friend should be able to tell you if there's any freon in the system. It may be just low.

Does system have a history of leaks?

 

Similar problem, but in a 96 C220

I too am having A/C problems where it is not working properly. I have run the diagnostic trouble codes and came up with ...

23*3
41*6
42*1

* is used in place of "degree"
Not sure what I can do with this information now any help from the forum will be greatly appreciated!

 

I too am having A/C problems where it is not working properly.

I don't know anything about codes but wanted to say I had a similar problem with a 1997 C-280 and found one on eBay for ~$285. I called one day to complain about it not working and he asked me what the temperature was outside. When I said 55 he chuckled and said your car has a auto control and it won't turn on at that high a temperature. I hope that's your problem too.

 

you might want to check the compressor clutch too... sometimes its not just the ccu unit that throws it off... check your cabin filter too while you're down there. mine was like that before i spent 950 on parts and labor..new clutch, new filter, new ccu... it was a big ding on the pocket but am sure glad it was fixed... california weather nowadays can get very unpredictable...

 

I bet for a new clutch in a/c compressor, on ebay there are some complete compressors (clutch included) may work for you, normally electrical system does not fail if you have working heater..

Most of vehicles with a/c problem. comes from faulty clutch, however it has to engage all the time since this type of car has automatic climate control..hard work for compressors.