Check to see if it happens with the heater defroster if so the blower motor resistor is bad if it works with no interruption then it could be either a broken vacuum line or the ac doesn't have enough Freon in it because it has a leak in the system the cycling switches high/low pressure turn the compressor off to avoid damaging it if this is the problem adding Freon without finding the leak will not work and you will waste your $$$ ac systems are sealed and never ever need Freon unless there is a leak in the system which must be repaired and the system put under vacuum to evacuate any air inside there is no reset for the system if the ac starts and stops when rpms increase its either one of the above described ok