On my car, same year and model, I have to rev the engine to get the compressor to kick in- been that way for years.

Once I do that, it's fine. If I recall, there's a vacuum operated switch on the driver's side inner fenderwell that enters into the mix somewhere.

Of course, this is assuming you have enough refrigerant and good hi- low pressure switches.

__________________
1968 230S Automatic, Elfenbein
1975 O309D Executive Westfalia Camper Bus, Blau/ Weiss
1972 280SEL 4,5 Dunkelrot
1966 VW Type 34 "Grosser" Karmann-Ghia
1963 VW 1500 Variant Pearlweiss
1969 VW Variant Automatic, Perugruen
1971 VW Squareback Automatic, Clementine Orange
2001 E320 4Matic Wagon- Our belated welcome to the 21st century! Polar White
1973 280SEL 4,5 Sliding Roof "The Bomb", Dunkelblau.