My dad has a 93 chevy cheyenne with a 4.3 v6. A couple weeks ago I added some freon to the system and everything was fine. After running the system for two or three days it stopped working. After looking over it I see the compressor is not kicking on. When I jump it, it comes right on. I can't find any relays or disconnected wires. What else should I be looking for to fix this?

Put some dye in the system and check for any leaks. If you lost all the freon that you installed, the compressor won't turn on.

I tried already and it won't take. That's when I decided to jump it.

Try replacing the pressure cycling switch. If it's not reading properly, it thinks the system is empty and keeps the compressor from turning on.