Hi Forum, I've noticed a lot of A/C posts in here lately, so here's another!

I recently put in a new A/C compressor (rebuilt, from air parts), accumulator, VOV, and all new O-rings in my 1995 960. I then brought it into a shop where they evacuated and recharged the system. It worked ok (not exactly freezing) for about 2 weeks, but then the compressor stopped engaging yesterday. I waited a little while and turned the car back on, and the compressor reengaged, but is now making a sqeualing / squeaking noise which can't be good.

The compressor came with explicit instructions to not add any oil because it was already done at the factory, so I don't think that's the problem. Is it possible that the mechanic didn't put the right amount of PAG oil and refrigerant in? When it first shut off, I checked the pressure on the cap and it was ~70psi. The condenser is the same one that came with the car; is it possible that reduced flow from a clogged up condenser caused the problem? Is the compressor done for at this point or is it salvageable?

Thanks in advance!

Kip