Tail/Running Light Problem

[Rockwood Travelers]

We recently upgraded to a 27' Rockwood Forest River Ultra-Lite. During our very first short trip late in the season (late September) we developed a problem with the tail lights and running lights. The running lights on the front half of the trailer work but the tail lights and running lights on the back half of the trailer do not. Early on this problem was intermittent but now it seems to be persistent, which in the whole scheme of things it good since we don't want to be running down the road not knowing if the tail lights are illuminated or not.

There is a flat 4 hook up on the rear of the trailer that doesn't have the look of a factory installation. This situation has blown the fuse on the tow vehicle once but it seems not to blow it every time I turn the lights on. I find it a bit puzzling that the front running lights work but the rear's do not. It's been my experience that if there is a problem it generally affects the whole circuit. If the fuse had not blown I would tend to believe it is a broken wire somewhere between the front and rear of the trailer.

I haven't had the time to investigate until now since my busy season is from Sept. to Nov. I want to get this figured out before we come down to crunch time for our first planned trip which is Memorial Day Weekend.

[maskins]

sounds like a loose ground or loose connection in the trailer plug at the end of the camper. Trace it back to where the connections are made.

[Bama Rambler]

Do the brake lights & turn signals work?

If they do I wouldn't suspect a ground as the ground is common to both brake/turn & running/tail lights.

Since a 4-way plug has been added I'd suspect a loose connection at or near the rear lights. I'd pull the lights and inspect the connections. And if that doesn't fix it I'd start working my way forward.

[Rockwood Travelers]

Originally Posted by Bama Rambler

Do the brake lights & turn signals work?

If they do I wouldn't suspect a ground as the ground is common to both brake/turn & running/tail lights.

Since a 4-way plug has been added I'd suspect a loose connection at or near the rear lights. I'd pull the lights and inspect the connections. And if that doesn't fix it I'd start working my way forward.

Bama, the brake lights, turn signals and brakes operate perfectly. I'm in full agreement on the ground possibility.

[dbledan]

If the taillights and blinkers work it's not a ground.

I would check the 7pin wiring box. To me it sounds like either those lights branch and one of the wires came loose or wiring somewhere along the line has come disconnected.

If it disconnected along the line you can pull each of the lights and see if the wiring is attached continuously or if a crimp came lose.

[eldonj]

We had almost same thing happen. Have a 2017 crusader 340rst that I addeded a furion observation camera to and tied hot wire in rear running lights. Going down road we lost signal to camera monitor and then might come back on. Thought I just lost signal, but when we got home and backing in wife said we have no tai or running lights, do have front running lights,, brake lights and turn signal. I figured it was something to do with my connection for camera. Took camera off and checked connections and everything came back on.. hooray fixed,,,until next trip and did something. Front running lights but no rear tail light or running lights and of course no camera. Still have brake and turn signal. With friends help we we able to trace front running lights wiring and appeared they continued to back lights. Could not follow wires any further ,so assumed there was a short somewhere but could not follow it. I ended up running dedicated wire from junction box located under pin box. Located wire for running lights and ran under trailer back to 1st running light that didn’t work and all is well. Talked to a rv technician later and he said they had samething and he found that when manufactured the front running lights wher wired continuously then run up behind the breaker box in side trailer, then wire was tied into that for rear lights and he found a bad connection there. Not saying that is your problem, but maybe something to look at

[Rockwood Travelers]

Originally Posted by eldonj

We had almost same thing happen. Have a 2017 crusader 340rst that I addeded a furion observation camera to and tied hot wire in rear running lights. Going down road we lost signal to camera monitor and then might come back on. Thought I just lost signal, but when we got home and backing in wife said we have no tai or running lights, do have front running lights,, brake lights and turn signal. I figured it was something to do with my connection for camera. Took camera off and checked connections and everything came back on.. hooray fixed,,,until next trip and did something. Front running lights but no rear tail light or running lights and of course no camera. Still have brake and turn signal. With friends help we we able to trace front running lights wiring and appeared they continued to back lights. Could not follow wires any further ,so assumed there was a short somewhere but could not follow it. I ended up running dedicated wire from junction box located under pin box. Located wire for running lights and ran under trailer back to 1st running light that didn’t work and all is well. Talked to a rv technician later and he said they had samething and he found that when manufactured the front running lights wher wired continuously then run up behind the breaker box in side trailer, then wire was tied into that for rear lights and he found a bad connection there. Not saying that is your problem, but maybe something to look at

This sounds very similar to our problem! The only difference is we have a flat 4 connector wired in at the rear of the trailer and this problem blew the fuse once so there must be a short somewhere. I thought there was a tool and a way to pinpoint a short but haven't ran across that information yet. I may be in error and that type tool may not exist.