I think compressor, what say you? (click photo for video)

 

Talking about that knock noise in the compressor? And it's cycling too quickly or were you doing that?

Have you tried an evac/oil/recharge?

 

Yeah, wonderign about the clatter when the clutch is engaged. The A/C was cycling fast because it was a cold day and the car has climate control (so tries to maintain a constant temp in side cabin, which it can easily do without the refrigerant).
I think it might be the compressor myself but I've never heard a rotary compressor die, only ever had reciprocating compressor on my old cars.