SL/R129: Help to diagnose my AC


Compressor isnt running/doing anything.
I’m at bit of a loss on where to start. A shop (ended up not trusting them- long story) said my refrigerant was checked and topped up. They said to me they thought the compressor is seized. Unfortunately I can’t verify the amount of refrigerant. This might be true but I’d like to verify it.
Can the compressor be jumped? I’ve undone the 3 prong connector onto the compressor. What can I check here without risking damaging anything? Is it possible to jump the compressor or do any checks at it’s plug? One wire I believe is for the magnetic clutch and I think the other two might be from the ‘base module”. Is the base module the big multifunction relay that controls wipers/blinkers etc?
I have access to HHT-WIN but I’m not in the least familiar with where to look on it. On that note, is there any good tutorials on it? Running though what modules it can check and what results mean?
I was told today the front of the AC Compressor should spin with the engine off. Is this true?
Any pointers appreciated. Thanks
(attached is the wiring colours I’ve found at the compressor) ec is for electromagnetic clutch. I’m guessing this is power. A slightly thicker wire to the other two.


