1999 Mercedes Benz CLK320

I got 99 Mercedes CLK 320 coupe. My heat works perfectly fine, it blows air without any problems. But my ac is not working. Even when i put it to the lowest/cold it blows the air in the cabin but its not cold instead its the same temperature as outside in the environment. The ac liquid is full, radiator fan is working perfectly. Then there is a red light on at ac control panel called EC. Even when the ac is off. I have double checked all the fuses and they are fine so i m confused and please help me out...
Thanx