EC light on. no air con

[television]

All lovely and cool in the car today so all good in my SLK world!
Next thing on my list is the rear screen demister.

They are not that efficient, have you done any checking, does the lamp stay on for the 17min duration

 

[rose5691]

The light stays on but I haven't waited to see how long for. There is no voltage reading on connections either side of the screen either. I may be living in denial as I'm sure I have read somewhere here that it is controlled by the pse pump which is still not working properly. Other symptoms being;

no courtesy light
no alarm.

May have to live with it though. We have discussed this before and you kindly tried to fix it

 

[television]

I am certain that this is not part of the PSE pump at all

 

[rose5691]

That's good news then! I've checked the relevant fuses and they seem fine. Next I suppose I should just trace down until I get some voltage...

 

[television]

It would be handy if this could be carried on in the right section

 

[rose5691]

Oops, sorry:Oops:

 

[mrahman136]

Hi, I have a w203 2001 c270 that has no a/c. the system has been pressure checked and no leaks etc, fresh gas etc. no warning lights on the control panel. the twist knobs repsond to temp changes etc but no a/c cold air. the last person to look at it said there was no power to the compressor. the compressor has actually been changed several times that I know of (the previous owner was a friend who spent a fortune on them and they kept breaking) is something else causing this? I cant be sure if the current compressor works or not.

 

[television]

It is the pressure sensors that allow the compressor clutch to energize, often the wire feeding the clutch breaks just where it enters the compressor, this is if you car has this type of compressor.

 

[2247bspl]

The EC light is also stuck on on my W220 S320CDI I tried the above procedure, and managed to get the fault codes, and then reset. The light then would turn off. However almost immediately it would come back on and not turn off again. The fault codes were 1257 a & b, after reset only 1257a remains has anyone got any ideas what this code is?

I have also have issues with my external Temp sensor, could this have anything to do with it?

All information gratefully received.

Thanks Gary

Gary, Did you find out what fault code 1257a was and how did the problem get resolved? I have the same problem with a non-functioning Air-con on a W220, 2001, with the error code and EC light on returning immediately after reset using the on-board procedure. Also, there is \ was an outside temperature issue. Whilst the error code for that issue reset without returning, the outside sensor value shown in the climate control test window is different from that shown in the instrument cluster window (Circa 15C in the test window and 10C in the Cluster window). The Instrument Cluster value seems about right. Does anyone know if these are different sensors and does it matter that the values are different. Air-con still not working

 

[saeed_mohmd]

My Issue is solved:

I was having EC light on in my 2002 C-Class so compressor stooped working...
I added gas but still light is on...
I made doaa (prayer) to allah to help me solving this problem.

Then I opened the front panel and removed the AC unit out and unplugged it from the wire harness.
Then I opened the unit itself and cleaned it by air then reconnect it again.
Then it is worked and the light goes and compressor started again...

alhamdulellah

 

[Lance]

Ive just bought a W203 year 2000 and EC light was stuck on. I had assumed that the Aircon just needed regassing as I had a similar issue on my W211 in Spain. I took it to a car electrical place and they regassed it and light is now off and nice and cool. There was some issue with "flaps" whatever that is but it's now nice and cool as and when required and light is off. Cost me £60 in total for the aircon service.