When I got in my truck today I turned the heater on and it started to blow cold air even after the engine warmed up. I looked under the hood and the a/c compressor was kicking on and off. Would it be a relay or switch? I checked all the fuses and they were good. I'm no electrician, so what gives?...Oh yeah, 00' f150 v6.

 

I'm no genie at ac controls but I'd say that your Temp switch **** is messed up, unfortunately I guess you have 2 options..u can either:
-Buy a new ac control box
-Troubleshoot! check your **** isn't cracked and just turning freely, check your harness didn't come loose (both these things can happen if you have had an aftermarket radio put in BTW), check a wire isn't pinched, (also could happen if radio was taken out or any wiring under the dash ie; alarm, cb, brake control...)
Good luck!