Running Lights Don't Work 2015 Jayflight 28BHBE TT

[RUSSELL5000]

Had an opportunity for our first trip with the new TT this past weekend. All hooked up and ready to go - no running lights. Brake lights, turn signals, electric brakes - all working, just no running lights. We were only travelling in the middle of a sunny day and so went anyhow.

So, now I would like to troubleshoot. I was thinking:

(1) Get voltmeter and check voltage at the connector on the truck - make sure I have juice coming into the trailer line. I don't think this is the problem because I just towed another trailer and running lights were fine.

(2) The line runs into a box mounted on the trailer frame. Open the box and make sure all connections are sound.

(3) If all connections are sound then check voltage at each wire according to the color code from the owner manual.

If I have juice at each wire correctly and solid connections then where would I go from there?

Thanks!

[el-dubya]

I had a similar problem on a pop-up we had and I finally found a bad ground connection on the frame at the rear of the trailer. It was tight but had rusted and was not making contact. There may also be a ground at the front of the frame where the tow vehicle harness is attached. Hope this helps! LW

[Bob Landry]

If you have all of the voltages from the truck's plug, you know that's good. Go to the trailer. make sure you have a good ground from the neg post on the battery to the trailer frame. Then connect a wire to the pos side of the battery and touch each of the pins on the trailer plug and verify that each of the lights work. if they do, then you have eliminated a broken wire, bad grounds, etc., and you won't waste a lot of time with what-ifs and second guessing. if you can make all of the lights work using the 12V from the TT battery, all that is left is a mismatch between the plugs. Trailer manufacturers like to use cheap components, and they usually use Bargman which are known to have issues. I replaced mine with a Pollack and have had no more issues. I'm sure there ae different brands out there, but Pollock seems to mate well with just about everything.

[RUSSELL5000]

OK, thanks for the tips. I'll check the ground connections and get a jumper to check the trailer plug/line.

Tonight is the truck. I hope I get to rule things out on that end.

[thomasmnile]

Originally Posted by RUSSELL5000

OK, thanks for the tips. I'll check the ground connections and get a jumper to check the trailer plug/line.

Tonight is the truck. I hope I get to rule things out on that end.

OP: Before all else, check the fuse for the running lights located under the hood in that power center thing, or whatever Dodge/Ram calls it. Experienced the same situation as you in May, though when we started out the marker lights were working. believe it or not there 3 or four fuses in that box that protect multiple exterior lighting circuits on the truck that could also impact your trailer. Believe the particular circuit is 15 amp and referred to as 'parking lamps' on the inside of the power center cover. I don't remember the the fuse #. Granted, my truck is an '05 but I'll bet the wiring/circuit scheme hasn't changed much over the years for the body. And, they are the mini fuses so chances are it won't look bad when you pull it but more than likely is.

[RUSSELL5000]

thomasnmile,

I did a bunch of testing and looking and found no power for the running lights at the connector pin. It was indeed a blown fuse.

Now I am wondering if there is something in the travel trailer running light circuit that has shorted to ground; i.e., something must have caused the fuse to blow.

I would think I could take my meter and check the resistance between ground and the running lights pin on the travel trailer plug. How much current should running lights pull?

Thanks!