Ok, here we go. I have a 98 C280, the other day I noticed the AC wasn't as cold as it should be, so I had it filled and put some dye in to search for a leak later. About a week later the EC light came on and stayed on, and it is yet to go off. The air gets cool but not cold. I did a forum search and saw where you said it could be one of two sensors. However, is it possible that's it the compressor? I sent a private message to the person who had the same problem but I haven't gotten a response. Also if you could post any diagrams to help me with whatever problem you think it is, I would greatly appreciate it. Anyone else who has anything to offer please feel free everything helps.

Thanks,
FA

 

first you must check if there is still a leak.

if the pressure is less than 6 bar with engine running and compressor "on"... then you need to find that leak and fix it.

if the pressure is more than 8 bar (engine running and compressor on), then one of the following sensors got problem (attached). most preferably the refrigirant sensor.

[IMG]local://upfiles/1/65ADFB09C2EF4B7C960E57B4FDA0ECCA.jpg[/IMG]

[IMG]local://upfiles/1/DBB2CBD222DC4654ABEE0FB01D5254A0.jpg[/IMG]

 

You the man! I may need to ask some more questions, but hopefully this is it.

 

Since ive owned my 97 C230, ive been having that exact same problem, depending on how hot it is outside. on a summer day when its 95, the A/C condensor/clutch turns on and off, randomly. When its dark and starting to get cooler out, the A/C blows Ice cold. I had the entire A/C system under the hood replaced, and the problem still occurs. The mechanic told me it was my in-dash control unit, but I think its these sensors you are refering to. Any ideas?

 

you got sun sensor?

 

I'm not sure what that is.