what's the difference between sanden mfr and hadsys mfr compressors? i have a 1994 honda civic hatch back dx 1.5 liter. the compressor don't come on when i press the ac button but i have power all the way to the relay and it seems to work fine. if i hook up power to the compressor, the clutch will grip and spin. it will make winding noises. the pressure is also high and will stall the engine at certain times. i got cold air for a while when testing but not anymore. what's my problem? i can do mechanical work but i'm not good at diagnosting. planning to get this kit and have a shop flush and service the system. one shop quoted me $497 for parts and $311 for labor w/out tax. is this reasonable?

 

It may not be the compressor, could be way overcharged causing this too.
Get it checked first before buying new stuff.