Air Conditioning?? HELP

i have an 89 silverado, and my pully on the air conditioning compressor seized up. the noise was a ticking or clicking sound that occured whether the ac was on or off. is it the pully bearing, or the clutch. and how do i fix the problem, and where do i get the parts necesary. thanks for any input.
Wade

If the compressor is seized, just get a replacement unit with the clutch. Most parts stores should have this one. Good Luck.