AC on all the time....HELP

[steves1967]

I've got to figure this out and don't know where to begin...90 burb front and rear AC. The plug under the hood, that connects to the compressor is all burnt up, when i do plug it in (rig it), the compressor starts running, even if the dash controls are off, or set on "heat". The damn compressor runs all the time- I notice a burnt wire smell, and saw smoke once in the truck when i plug the compressor wire into the compressor and drive around town- where should i look for the problem?? Thanks-Steve