The a/c in my 1982 240D does work but the compresor cycles on and off. I have the thermostat turned all the way up (coldest position). but the a/c act as if I have the thermostat turned down (to a position that is not as cold). the air blows cold for about 30 seconds then blows unclooed air for about 120 seconds then cold air for about 30 seconds again and stays in that cycle. The car never cllos don because of that. Please some one tell me what I should look for to fix or change and where to fond the part I know it is in the dash somewhere but I dont want to tear into the dash untill I know what I am looking for.

 

I forgot to mention the freeon is fine.