Wire nuts will work, as well as butt splices. Is there not a hollow cavity between the light and the inside shelf where you could run the wires to be hidden? Reason I say that, it the last two Jaycos I've had I did the same thing and the overhead cabinets have a false bottom in them where they run the wires for the bed lights. In any event, use some sort of mechanical connector or solder to join the wires. If using solder, use Rosin core solder, not acid core, and tape or use heat shrink tubing. Do not just wrap the wires together with tape. If the wiring is going to be exposed, try to protect it with something. I added some receptacles in our last unit, and I used a hot melt glue gun to secure the wiring back in the corners.
Randy, Karen & Abby (Pom-a-Poo)
2014 Eagle HT 27.5RLTS
2015 F250 Super duty 6.2L full trailering pkg.
Shenandoah Valley of Virginia