I had the A/C on and after a short while my car started to squeak loudly, like it was 50yrs old. This does not occurs when A/C is not on. I thought maybe it was the shocks but the car does not bounce.
Squeaking noise when A/C is on. on 2003 Volkswagen Jetta TDI
It might just be a belt or the tensioner. Have it checked out.
Sounds like the fan clutch or compressor if the noise comes and goes with the A/C.