1993 400SEL a/c issue
 

Upon cold start, a/c blows cold. After driving and engine comes up to temp, it blows hot air. Freon charge is full. But compressor doesnt come on.

Any suggestions for relay switch check or Klima?

Many thanks

Just maybe
 

I have had a similar problem, turn off the igniton and restart. If it comes back you have a slipping belt, It seems they had a sensor in the compressor that compared it to engine speed. I drove me crazy, I would accelerate hard and the AC would quit, or drive thru a puddle, MB replaced belt amd tensioner. The issue is gone and has been gone for two years.

Thanks!