Aircon not working

[ahoythere]

I have a W210 (E300 TD). The EC light can be switched off and on by pressing the EC button but when I switch it off, I'm not getting any cool air.

Any idea what the problem might be...faulty temp sensor perhaps? (My problem is slightly different to the problem in the sticky post in that my EC light can be switched on and off).

Thanks,
ahoythere

 

[karlefr]

Regassing!

 

[brandwooddixon]

Check that the compressor pump is actually running when EC is switched off.

Normally if low on gas the EC light comes on permenantly.

 

[rapide]

not cold

thats right if the gas gets to low the compressor wont cut in! push the economy button to get the light out turn dials to blue sector on dash and up the bonnet ( engine running of course)and see if the clutch on the compressor has cut in , if unsure get someone to push the button while you look at it and you should hear it click in or out! if its not working then its low gas! also have look at the drier unit to the front and right its got glass button / window on top to give you a visual on refrigerant flow ( liquid) it should be bubble/gas free when running ok! all simple checks. you are getting good air flow ie; the cabin filters not blocked?

 

[ahoythere]

Thanks for the replies. My car is going in to my local garage today and I shall pass on your advice. The mechanic who serviced my car the other day did say that he had tested the gas pressure and it appeared OK.

I cannot hear the compressor cutting in when the aircon is switched on (EC light off) which is strange because two days ago, I thought I could definitely hear it from inside the cabin. Now, either sitting in the cabin or with the bonnet lifted, the noise level is the same whether the EC light is on or off. Air flow is fine by the way.

I'll report back on the mechanic's findings.

 

[ahoythere]

Well - I've just collected my car and it's hats off to rapide for identifying the problem! It turned out to be a 'clutch' problem. The clutch (inside the AC unit) which causes the compressor to cut in had dropped off! It is held on with a 10mm(?) M6(?) bolt which had come undone. The mechanic reaffixed the clutch and recommended that I go back next week so that he can check that it is engaging and disengaging okay. I don't think it is! On the drive back home, I was blasted with cold air even after switching the EC light back on. Ho hum, back to the garage...

Can anyone advise me on the whereabouts of this 'clutch' and for that matter the aircon unit? If I'm looking into the bonnet from the outside, leaning over the radiator grill, where is the aircon unit located exactly? And can anyone offer advice as to how to get the clutch to engage/disengage properly?

 

[robs-mbz]

The Compressor is at the front right of the engine as you look under the bonnet. The clutch is part of the hub of the pulley on the compressor. If the clutch is not energising with the EC switch off and the fan set to at least speed 2 then my guess is the gas pressure is low. There is a pressure switch in the system that isolates the compressor clutch when the gas pressure is low. This is to prevent the compressor running dry and self destructing. The pressure switch could be faulty or the guy who looked at the system last could have disturbed the wiring to it. My money would be on low gas pressure!

 

[ahoythere]

If the clutch is not energising with the EC switch off and the fan set to at least speed 2 then my guess is the gas pressure is low. There is a pressure switch in the system that isolates the compressor clutch when the gas pressure is low. This is to prevent the compressor running dry and self destructing.

But the clutch is engaging and now seems locked in position. The result is that the aircon is on all the time. The problem now is that I cannot turn the aircon off.

 

[rapide]

air conned!

it sounds like your man has jammed the clutch / locked it up! possibly with wrong bolts? get it looked at right away, if its low on gas and shouldnt run ( low gas cut off switch) and he has locked it up to run, the compressor will suffer! use someone, ei; recommended merc man with a/c knowledge. ask on here for your area. all the best.