Compressor cycles on and off

I just got the AC in my Duster up and running, all stock components, R12 Freon, fresh oil etc. It blows cold but the compressor clicks off about every 30 seconds. It stays off for about 10 seconds then comes back on. Freon is full, pressure is good. I checked the low pressure switch on the dryer and the power coming to the switch is being interrupted. Is there something in the car under the dash that is cutting power? It hasn't really been an issue because it stays cold but I don't remember them working this way.. Thanks!!