Happy that you resolved your issue. Just thought that I would throw something out there for you to think about. I added an extra set of lights on the back of my rig. I have them set to trigger with a switch or trigger off of the reverse lights. You could actualy extend this out to a trailer? Just thinking out loud.

 

The 7 pin connector is made for rvs. The number 7 pin is backup on the rv end of the plug and when they come installed from the factory like on a Ford truck it would be provided pwr when in reverse. The pwr pin is for charging your rv batts while driving and towing the rv. I had a Dodge truck and replaced the stock wire for the pwr pin with a very heavy gauge wire for carrying more current and used that to pwr up all kinds of stuff when camping.
I like that adapter that you posted on here. That is the only one I don't currently have in my box. What kind of trailer has that 5 pin connector?

 

I don't really know for sure....but I believe boat trailers use them which have electronic brakes. I believe when you put it in reverse it unlocks the brakes of the trailer.

I Just needed a 4 pin adapter and saw the dual 4 and 5 pin and figured I might as well, get the dual adapter just in case.

Then I found out I needed that 5th pin for the hitch cargo basket lighting that I was hooking up which I have posted in this write up thread.
https://www.jk-forum.com/forums/show...=1#post1887433

 

Thanks for the feedback and very nice write up by the way.