So what powers the relay that fires your engine? Make sure that the pink wire from your switch pin #5 to the BCM has power when you turn the key to start. If it does, your BCM should be sending a message to the ECM to start. ECM sends power to the start relay on the yellow/black wire to the control side of the start relay. Check that. This is what the wiring diagram for my 2008 model says. Check your STRTR fuse in the underhood fuse block.
Get a wiring diagram for your year at GMUPFITTER.COM, body builder manuals, then look for your year and model and get the Electrical manual (separate from the others) and follow thru the steps that would occur during the start process, see where you have power and then where power fails.
So it turns out that whoever had the truck before me had bought it from a buy here pay here place. It had a gps tracking system in it and they wired it so bad that the wires were shorting out the box. Removed it and used good wire connectors and boom fired right up. Thanks guys for the suggestions