I am hooking up a brake controller in my 1994 F150 XL. Found the factory plugin and found the wiring is not the standard colors. So I have red as battery +, white as ground, green as brake. Is the blue going to the trailer brakes? If yes, where do I tap into it? Seems there are fuses for a wire socket in the engine fuse block, but I can't seem to find the 10 pin socket I see in wiring diagrams that the trailer wiring hooks into. I am assuming that this is a factory socket for a trailer wiring harness that I do not have.

I've tapped into each wire and ran my own wire back to the 7 pin rv connector. So I am now just curious where the ten pin connector is. By the way the 10 pin connector has two pins X'd out and one not associated with a wire.

 

Yes you are right, the green is brake Lights and the blue goes to the brake coils. That is the standard colors for Ford.
If you do not have Factory Trailer wiring then the Blue wire stops at the Firewall connector. The rest you will have to pick up at the rear of the truck.I have not heard of this 10 pin socket, Tell me about it. What Diagrams are you looking at?

Pin #2 is the Blue wire that stops at the firewall connector as shown in the photos below.

 

I'll scan the relevant portion of the diagram and post it. It is in the wiring diagrams in a Hanes manual for the truck. Great pics.

 

I do not own a Hanes manual but if it say there is a 10 pin plug in the wiring that goes to the trailer wiring it is wrong.
This is why I do not own one of the Hanes manuals.
They just copy from the Ford manuals. I have had a bad enough time with the errors in them let alone someone copying them and putting in more errors and trying to cover a lot of years with one manual.

I would like to see the diagram of what you are talking about, looking forward to seeing it.

 

Here are some diagrams of the C205 Wiring Harness with and without the Factory Trailer Wiring. The Bottom is the Trailer Relay Box that comes with the Factory Trailer Wiring setup.