I got similar problem last year.
Went to Riverview Auto in AMK, and they confirmed it is the compressor.
Even if you don't turn on your aircon or just in fan mode, the aircon compressor is still being driven, because it shares the same shaft as the alternator and radiator.
I was told that in my case it was likely the ball bearing of the aircon compressor, but you cannot replace just the ball bearing.
If not replaced, it may just failed one day, and the whole shaft will jam, stopping the alternator and radiator. And you car will overheat and without battery.
Riverview charge me around $750 (can't remember the exact).
BTW, it is not true that only TCM has the bracket, pulley, compressor, etc.
Any stockist will have them too.