GMC Repair: GMC-2001 Yukon airconditioning, crank pulley, sqeak

Question
AC had worked when I turned the car off but 1hr later it just blew air but not cold air.  A friend had checked the freon and said it was full.  Prior to that I was hearing a loud grinding (under the ront passenger hood) only upon intial acceleration when I had the air on.  Now I don't hear that noise.

I have a 2001 2WD Yukon - 4.8 with 80,00+ miles and was in fairly good condition except for a constant sqeak since I bought the truck new.

I did have a history with the air and loud noises when I turned the air to MAX but that seemed to be fixed as least for the past two years I did not hear it

Answer
Your A/C compressor may have locked up, but the first thing I would check is the belt. On this truck the A/C has a seperate belt from everything else. Look at the crank pulley, there should be a belt thinner than the main belt going from it to the compressor at the bottom passenger side of the engine. More than likely the compressor was locking up and it threw the belt.