If your vehicle was ordered with Tow wiring:
Vehicles equipped with the trailer tow package also include an electric trailer brake wiring provision that terminates at a connector located on top of the large body harness connection under the instrument panel to the left of the brake pedal.
If there is no connection, then the vehicle probably didn't come with the Tow Package & you would need to purchase Aftermarket Tow wiring & Brake Contoller Harness.There are a number of On-Line Trailer Wiring Shops or you may be able to purchase locally at a Trailer / Hitch Shop
Does your truck have a Tow Connector at the rear bumper now with wires ran to the cab?Is it Factory installed or Aftermarket?
If the 4 pin was Factory & you converted to 7 pin, by adding wires, then you would have to splice into your new wiring, as there would not be a plug for the 4 pin.
That was my question..........Is this a Factory Tow wire harness (4 pin) or aftermarket?
I will relist this, as I have very limited info on the 4 pin & if it is Aftermarket
Hello, my name is Mark.
If you are unable to find the factory plug in for the controller, then you will need to wire this yourself.
Your controller will have 4 wires.
One is power.......I'd run this direct to the battery using an inline fuse.
One is ground....
One is the inout from the brake light switch.........this is a white/tan wire at the brake switch.
And the last wire, I would run direct to the 7 pin connector, running the wire along the frame rail.
Here is a pic, if it helps you.