Toyota Repair: 91 toyota previa a/c, toyota previa, air conditioning

Question
Especially when I first start the Air Conditioning there is a high pitched whining noise.  It sometimes coincides with pressing the gas.  That is, sometimes it comes on when I press the gas and then is gone when I let up.  Sometimes it is there even when I don't press the gas.  There is no noise when the A/C is off.  Also it is not as cold as it used to be.  The noise tends to be less frequent after the A/C has been running a while but will still come back.  What do you think is wrong?


Answer
The first thing is to check to see if the A/C belt is tight and not worn, if that's not the problem there may be a malfunction with the A/C compressor, it may be starting to seize up for some reason or there may be another problem, if the belt is not the problem let me know and I'll try to help more.