Travel Trailer Power Wiring Diagram. If your truck has a built in 7 pin socket but you only need 5 of the pins. Same as 4 way system listed above but adds a extra blue wire for brake.
Complete with a color coded trailer wiring diagram for each plug type including a 7 pin trailer wiring diagram this guide walks through various trailer wiring installation solution including custom wiring splice in wiring and replacement wiring. My suggestion is to use a tester on your vehicle first to be sure of how it is wired then compare it to. Number 5 and 6 in the diagram below.
I attached a couple pics to help you see where the wire is at.
Find the metal clip that holds the panel in the arm rest. This is a really good box for wiring a trailer. Number 5 and 6 in the diagram below. Power electronics control unit.