I'm very naive on this issue. I just bought a home with a Corsair AC
which intermittently squeaks loudly (never when the AC person is here).
It always cools. It tends to squeak more often when just starting or
stopping, but sometimes continually. Sometimes, when it squeaks while
stopping, there is a "whoosh" sound at the end.

Is there any way I can tell if it's the blower fan or the compressor?
What will eventually happen in either case?

Jack