Trailer wiring issues??? Photos included

[sethsport]

2003 sport trac Adrenalin. As far as I know it’s the original wiring harness. I just re-wired my trailer and now I got nothing at all from the lights. The harness from the truck has the white,brown,yellow,green.
The harness from the trailer has white,2 browns, yellow,green. The two browns from the trailer harness look like they splice together inside the harness. I’ve got a good ground.

The Photos are of the trailer harness, the truck harness, and the harness connected together. The colors match. What am I missing???

 

[sethsport]

Also, the kit came with another harness that had just the white brown yellow green. Im guessing that’s the one that supposed to come from the truck which is basically what I’ve already got coming from the truck. I’m stumped...

 

[koda2000]

White is for the ground, brown(s) are for tail/running lights, green is for left or right (don't remember which) turn signal and brake light and yellow is turn signal and brake on the other side.

It's okay for the the browns on the trailer to be spliced together as there is no left/right for tail/running lights.

The white wire is required because you have to have a ground between the trailer and vehicle for any of the lights to work. You might think the trailer would ground to the vehicle through the ball, and it might, but that's not a good enough ground and the resistance will ruin something on your vehicle (don't ask me how I know this, a lesson learned from my first trailer).

Get your self a cheap test light (better yet a VOM) to test the output of your vehicle through the trailer plug.

 

[njbronco]

you mis-read the trailer plug. They cheaped out in manufacturing and just spliced both sides of the trailers wiring at the plug. It looks like two, but they are both soldered to the same pin under all that plastic.

Sounds like you have a bad ground.

I have a 6x10 utility trailer that pivots. I have to stick a bolt up front between the trailer and tongue so that it gives the whole trailer ground so the lights work. lol. one day I will had a ground strap. without the screw, I get zero lights. youd think something would ground out with all the rust and the pin holding it down, nope. Not even with a half ton of bronco and explorer scrap metal on it.