I have a 1998 Hombre 2.2 (base model) I have just installed a Factory a/c system out of a wrecked truck. My question is. Do all trucks come pre wired for a/c from the factory or not. I can't seem to find any wires for the pressure switch or compressor.or any under the hood. There is a place in the electrical box under the hood for a relay, but no electrical contacts. Thanks in advance