Are you referring to the exterior amber and red clearance lights, the porch/utility lights, or the interior lights?
If you are referring to the exterior clearance lights, I don't know for sure. I wish I did. The TCs are pretty rare in my part of the country. I want to think that there's a cord that you plug in to the TC and then again to the truck plug that's the same plug you use for towing a trailer. I'm not sure where this plugs in, hopefully someone can help you out with the location of this.
2007 T-286SR Cherry/Granola, #6236, original owner, current mileage: 9473.8 (as of 6/18/21)
1997 T-2653 Blue Denim, #5471
1979 12 1/2' MC, Beige & Avocado, #4639
Past Sunlines: '97 T-2653 #5089, '94 T-2251, '86 T-1550, '94 T-2363, '98 T-270SR