So in that picture, it shows the ground to the trailer frame, assuming it is conductive metal. If your trailer is aluminum, it may not work. My experience is that the ground wire connections to the frame, both at the front by by the harness connector as well as at the light fixture itself corrode. Then the lights don't work. You can re-use some of the wires currently on it. So just splice into that white ground wire from the harness to each light. So you'll have 3 wires going to each taillight, the two in the diagram and one more for ground. There is another wire lead on each taillight for ground. Many people just wrap it to one of the studs that holds the light on the trailer, thus grounding to the trailer frame. That will work for a while but I say connect it directly to the white wire at the plug, and seal all the connections.

The top, vehicle side connector you do not use as your truck already has that fitting. Save or throw away. It's needed for cars and the like without towing packages where you need to splice into the vehicle taillight wiring.

 

Thanks for all your help. I am going to take all the wiring off tonight, see how far I get with running the new wires. It'd be alot easier of the waverunner wasn't on the trailer lol.

Thanks again for your help!

 

Well took the old trailer lights off, the tail lights themselves didn't even have grounds coming from them like these do. Going to bolt on the new ones tonight, run the wires and should be good to go. Thanks again

 

Ok, so I took all the old wiring out. I ran the new wiring, bolted on the lights - but only the brake lights and the signals worked, the parking lights didnt. I couldn't figure out for the life of me why the hell the parking lights didn't work. I got fed up, spliced the old harness into the new wiring, and boom it works. Talk about confusing.. something so simple turned into two and a half hours last night of trouble shooting. Any idea what could have caused this?