[2Tight]

There's a low Freon level sensor that once you hit that threshold it will cycle the compressor all the time until it kicks off completely which isn't usually too far behind. Try to top off with whatever refrigerant was used. More than likely though you have a slow leak at the compressor or in one of the connections. If you live in a very hot climate I don't think you will be happy with an R-134a conversion unless 90% of your driving is done at freeway speeds, especially on an early car.