94 E420 (150K miles)

Bought it with AC not working

Replaced blower motor fuse,
Replaced climate control unit in dash (old one was burnt out).

Problem: Blower motor will not run (in all settings), auxiliary fans will not run when AC is on, and the compressor will not engage.

When I turn the AC on I hear a slight hiss from underneath the dash, is there a vacuum leak somewhere?

What should I check/replace next?

Any help is appreciated. Thanks.

 

Go get partial charge or do it yourself and see if that triggers the compressor,if so you need to locate the leak and repair it,flush the system and have it properly refilled.
ohlord

 

I have tried to charge it and still nothing. It is as if the compressor does not accept charge.