ahm09

to summarize the story. i went to replace some faulty light bulbs and the electrician suggested to check the A/C refrigerant pressure even though the A/C was totally fine. anyway he said its a bit low and needs some refrigerant to be added so i agreed . after i went home and on the next day the A/C cools the air for a while then the cooling stops and i have to turn it off for a while before it starts working again. i went back to him and he tried to discharge some of the refrigerant to solve he problem but with no luck.
so finally i went to another electrician and had the refrigerate all discharged till vacuum then filled again with (1 KG) with 134a and the problem prevailed with A/C cooling a bit and then goes off with only hot air (NOTE: when the cooling is working the temperature in the center vets can drop till 3 degrees Celsius ).

But today it seems the A/C compressor wont engage at all. I'm not sure if its a faulty compressor or something else. so is there away to force the compressor on to check if it dead or any other suggestion.
Thanks a lot

I'm driving S320 2001

wallyp

There can be several possible causes for these problems.

One possible cause is icing of the evaporator core. The core temp should be just above freezing - if it is below freezing, ice builds up and blocks flow thru the core. After the system is turned off for a short period, the ice can melt, and the system functions again.

It sounds as if diagnosis of the system by a Mercedes tech who is knowledgeable about air conditioning should be the next step.

ahm09

Thanks for the reply Wallyp. i don't think icing would be the cause since i left the car for the whole night while outside temperature is around 35 Celsius and when i started the car the A/C didn't start at all . the technician said its the compressor , but im not sure if its the fact orhe just guessing . i as trying to find away to force the compressor on beyond the signal sent by the car computer to check if its the compressor or the car system
thanks again

ejack

Sorry to hear about your compressor problems. Perhaps a reset of your compressor may allow for further diagnosis. I think that a search of the forum will yield a compressor reset procedure, using your heating cooling temperature set keys. Generally when there is insufficient refrigerant in the system it automatically cuts off to prevent damage to the compressor. Your owners manual may also detail this procedure. Good luck

kbakhan

Ahm09, although it is very late to comment but are you still having the issue with your ac compressor? or it was resolved.