OK so I have read as much as possible here and elsewhere about trying get a handle on this. This is a 1983 300d. Here what I see and what I think:

Problems / what I see:

1) Compressor not engaging, can be made to do so by jumping wires on top of evaporator.

2) With compressor engaged 0 psi on both high and low side. added 1 can refrigerant with compressor jumped and running still 0 psi both sides compressor doesn't engage without jumpers.

3) center vents not blowing anything.

4) Fan blower motor starts and stops when I ask it to. Haven't checked heat.


Here's what I think:

Next test would be to take care to A/C shop and ask for Vacuum test?

If vacuum test doesn't show leaks then:

1)compressor may be bad even though is spins freely.

2) next steps would seem to be replace or rebuild compressor, evaporator and expansion valve.

3) Center vents unrelated vacuum system problem separate diagnosis and repair.

4) can't evaluate ACC until rest of system check out ok.

Does this seem like prudent course of action?

__________________
1972 280SE 4.5