Update- I will confirm with Ford but I did find that the Ford Trailer brake control Module is for this harness . The Redarc controller will attach to this.
I purchased the truck new, I'm original owner. Not sure where it is going. But it is going up towards the fuse box. I have not been able to find a solid blue wire in the harness or a yellow red. What's odd is it was the only thing that had blue tape on it. There are about 7 wires on the harness