I'm just getting around to installing the RAP relay and associated wiring. I did check the GM Upfitter Site to check on another connector and discovered this Tech Bulletin covering added relays to the electrical system. I'm sure no one wants to void the warranty on any of the computers or control modules in their truck. Adding a 1N4003 diode across the windings of the relay will keep induced voltage spikes generated by the relay when it drops out might save you some hard earned $$$$.
Just a word to the wise. Read the Tech Bulletin.
Ted