1991 Chevy Truck Air conditioner shuts off

I have a 91 chevy 1500 . When i turn the air on it blinks at me. So i unpluged the wires behind the glove box to make sure the conection was good. Then i turned on again the compressor cycled 8 times then the light on the dash blinked at me again and the compressor stoped kicking on. So ever time i unplug the wires to reset ac controls it cycles 8 times and shuits off and light blinks at me. Any ideas.