Mercedes Benz repair: a/c help, auto help, electrical problem

Question
My a/c all of a sudden went out while i was driving. It still blows air but not cool. It also blows heat to. It has freon and the lines are not leaking for some reason the compressor is not engaging when the switch is on. Could it be a electrical problem if it is how could i fix it or where do i start? I have a 1988 300e w124. thanks!

Answer
If you are sure that there is freon in the system check the front part of the a/c compressor. Is the clutch engaging> If not  check for signal to clutch. If no signal let me know. I believe that that compressor has an RPM sensor at the back . If the RPM signal is not received you will not have clutch engagement. check all fuses first and make sure that none are missing?
Let me know If you need a schematic

Ralph
Miami Auto Help Inc