I just picked up a used 02 C320 wagon and everything was fine until one day the A/C stopped turning on. It seems like it is stuck in economy mode because the "EC" light won't turn off when I press the button. It won't kick on the A/C or go into rest mode. In the manual it says that it could be because I'm low on freon, but I had it filled today and it's still having same issues. My mechanic thought it might be the climate control panel, but everything else seems to work fine on it. Temperature up and down, fan speed, recirculation, etc. I don't want to drop a few hundred dollars to replace it if it's not even the problem. Has anyone else ran into this before? Thanks.

 

Could be the a/c pressure sensor is not sensing that you have enough freon.Those C320 control panels have been known to go bad, mostly the display and temp buttons not working. It maybe one of those things a dealer or a a/c repair place can diagnose better.