On my 1983 300d the ac compressor was working fine before I evacuated and recharged the system. the only thing I replaced was the expansion valve. I have checked fuses. I have tried jumping across the connection at switch. I have check the pressure switch with ohm meter(ok). I have check voltage at ac compressor (none). I have run a jumper wire from battery to compressor and it works. What am I missing?
Thanks, Doug

Possible culprits include the CCU, evaporator temp regulator, compressor relay, and associated fuses/wiring.