Trailer T-Harness For Power Options

[Retired BLM Rig]

I wanted to add a 12V power outlet and lights to the bed of my truck, so rather than running a new dedicated circuit all the way from the battery, I decided to tap into the power that was already available at the trailer plug. You can buy a T-harness online, but it comes with smaller gauge wire and didn't access the circuits that I wanted to use, so I decided to build my own.

I sourced the factory connectors and terminals from Mouser for $23 + shipping and tax and started to crimp everything together. I used dual wall heat shrink to keep everything waterproof and taped it all up into a loom. Then I mounted a junction block behind my left taillight so I could add or change circuits at will.

So I ended up tapping into the:

• Battery + power for bed lights and a 12V power outlet in the bed (this is already fuse protected in the factory harness).

• Backup lights, so I can add extra lights in the future and have a dedicated switch in the bed to turn them on and off, without having to start and run the truck in reverse while I'm loading, unloading or camping in the dark.

• Parking lights, in case I want to add any additional lights in the future that turn on and off with my headlight switch.

I'll also be adding rock lights in the future and I want to be able to add a switch at the back of the truck, so I can illuminate the ground at night while I'm setting up camp.

Anyhow, here's some pictures with part numbers, in case you want to build your own 3rd Gen trailer T-harness:

[RustyPW]

[Mule007]

Sweet set up,,,thanks David

[KevinABQ]

Looks good.

[Retired BLM Rig]

If you don't want the hassle of building your own T-harness, you can just buy a gooseneck/5th wheel extension harness and cap off any circuits you don't want to use. They're available on many websites, but the least expensive seem to be on Amazon.

Here's the 3rd Gen harness.

And here's the 4th & 5th Gen harness.

[RustyPW]

If you don't want the hassle of building your own T-harness, you can just buy a gooseneck/5th wheel extension harness and cap off any circuits you don't want to use. They're available on many websites, but the least expensive seem to be on Amazon.


Screenshot 2024-09-09 at 11.39.24 PM.png


Screenshot 2024-09-13 at 7.58.22 AM.png

[Retired BLM Rig]

The only cargo light my truck has is the one on the back of the cab by the 3rd brake light. Since installing my Softopper canvas shell, that light has become useless. So I finally got around to adding my new bed lights and switch and power outlet.

A total of 8 lights, 4 on each side.

Routed the harness through the hole at the top of the rear bed corner post.

Installed the switch and power outlet at the bottom, just inside the tailgate.

[Mule007]