Hello, I just bought my 1997 mazda protege. It is running okay. When I first bought it used it started to make a squealing sound when I started it or went into gear. I broguht it to the dealear and they said it was the AC compressor. They tried to charge me 650 for it so I got the part myself used in good shape and got it installed for a total of 350. However now the problem is starting again and my check engine light is on. What should I do?

if you have over 60k on it, and haven't changed the timing belt, I am thinking one of your tb tensioners and probably locking up, I have come across that on Mazdas and VW's,

What caused the compressor to die? Did you check the high side and low side pressures before you pulled the compressor? I think you have a restriction in the system and the pressures are getting so high the belt slips and squeals. If you have gauges check both high and low side pressures and see if the high is too high and the low normal to low. This indicates a blockage. You should always flush the lines with a solvent and replace the filter and expansion valve when a compressor dies. That is probably what you would have gotten for the extra money the dealer wanted to charge. You can buy a book on car AC systems at the parts store. Good luck.