WHY AIR CONDITIONER BLOWS HOT AIR WHEN TEMP GUAGE GOES ABOVE NORMAL?

Most likely the thermostat needs to be replaced! A/C pressure goes up with engine temp. then the high pressure switch turns off the A/C compressor! Engine cools back down, when T-stat opens, and a/c starts working again. That's the way it's designed. Fix the engine tempture/cooling system problem and the air cond. will stay cold. There is nothing wrong with the Air Conditioner system!