Forgot to mention it's a 1994 GTR32.
I cant really describe the sound, but it's screeching to the ears and it's not like the normal/usual belt slipping sound that you get. Probably a mix of screech and grinding sound. It happens once I turn on the A/C. Stationary, on the move, on cold start up, when the car is warmed up - Same noise. I'm sure it's the A/C. But dont know what. The belt appears to be running too.
I havent tried if there's aircon blowing out cos the sound is so loud, once I hear it, I would turn off the A/C immediately.
If the A/C is not on, the fan blows out cold air or hot air depending on the temperature I set it to be.