I have a 1997 4-cylinder Accord. I am pretty sure the compressor is bad on my A/C but I'm not quite sure. I do know that the A/C does not work. When the fan is turned on and the A/C is on, only hot air blows. Also, if the A/C is left on for a few minutes, I hear a squealing sound. Is there a test I can do myself to see if it is in fact the A/C or does this require taking it to the shop? I plan on doing all repair work myself, but need to make sure I'm repair/replacing the right part.