I just pulled off the dash surround piece and was wondering if anybody knew what the wiring harness that is just to the left of the power port is for? When I say the power port, I mean the one with the little sliding door. There is an additional wire harness that is just plugged into nothing. Any ideas where it goes? Thanks

 

While I can't tell you what the plug is for, these trucks have a lot of options that the factory makes up there wire harness for.
So not all are used per the options present.
You would need to trace this on a factory drawing that has all the color codes and other info used to ID the plug and where it goes.
With a new truck, why are you looking in that area? not that is is important to me, just wondering.

 

I was trying to find a rattle that seemed to be coming from behind the dash area. When I saw the harness my mind said "Hmmm what option could I add"