Trailer light gremlins

Our ongoing saga of blown fuses and battery draining continues. My brother Barry and his spouse Mica hooked up with us at Goose Island the other day before they headed west (we have decided to hang around this area for now rather than heading to Big Bend.) Barry is an Airstream whiz, having renovated two old trailers from scratch and working on all the electrical, plumbing, and gas systems. He brought his tools and we spent the afternoon poking, testing, and drawing blanks for solutions.

The trailer running lights come on for about five seconds and then go off when the trailer is hooked up to the truck. We have power from the truck for the lights and traced the line into the trailer into some sort of relay/splitter under the couch. Barry is slim and crawled under the couch with his test light and found that the line going out of the splitter seemed dead. We sort of gave up, buttoned up, and had a nice dinner together. Here’s his followup guidance to me:

Just a recap, the green wire into the trailer stays hot to a small box of 4 wires, green out, black, and red. Black wire on box is ground. Red wire is hot, don’t know what it is. Green wire out may go to a junction of wires to various running lights. If you can find that junction unhook all wires and start hooking up one at a time to see if you can find the problem. Good luck.

So, for now we don’t drive at night. All other lights are working. And the project of sorting out the malfunctions continue. Fortunately, the days are getting longer.