Does this help?

Maybe this will be of some help to anybody who wants to add some lights to the bed of their truck and keep in line with the factory wiring. Here is the factory harness that is connected the wiring from the tailgate.

The part number for this harness is #4487 086 162380

If you were to remove the driver’s side tail lamp assembly you will be looking right at these wires where they exit from the center of the tailgate pivot from there they drop down under the body.



Here you see where they exit under the bed on the left side is the underside of the bumper. I do have a bit of extra wiring under there; those are my battery cables for my 8-D Deep Cycle battery that sits behind the wheel well.



Here is the end of the harness, it simply goes in-between the chassis harness and the plug that connects the drivers side tail lamps, so on a non-dually truck all of this mess would not be here and the 2 plugs would simply connect to each other.

By plugging in this harness it now supplies the power for the bed and tailgate lamps.

BTW the Scotch Locks were from the previous owner, I still find things he left behind that I have to fix. They are guaranteed electrical problem waiting to happen.



Here is the schematic for the rear left hand portion of the lighting system.

The square 4-conductor connector is the one we are talking about.

You might be able to find an aftermarket plug used for connecting trailer connectors without hacking up the wiring and splice into the harness that way.

I think they were made by Hoppy, Yup I found it.
http://www.trailerwiring.com/cgi-bin...cgi?part=42105



Sometimes a picture makes it easier to understand, let me know if there is something you do not understand.
Jim

Update..
I also just noticed that one of the site advertisers has connectors for just about anything with wheels, I haven’t heard of them before or know of the quality but they look good.
I would use the entire harness even the flat connector and integrate it into the rear lighting system.
If you haven’t already by now I would replace all of your marker lights with LED’s and install a relay to handle the load so the headlamp switch only powers the relay. Along with headlamp relays and your headlamp switch would probably last forever.
http://professionalwiringproducts.net/

http://www.professionalwiringproduct...0b545f6c8a0b0c