U-Haul 13' lights

[Jederick]

Hello,

I have a 1986 U-Haul 13" and I'm having tons of issues with my turn signals, brake lights, and running lights. Lots of shorting out and blowing of fuses. I think it's just the old wiring and I'd like to replace it from the plug all the way back to the lights. Has anyone else done this? I noticed on mine that the trailer has what looks like two sets of wires coming off the plug then they disappear into the tongue.

Like this:


So here are my questions:

Does each one of those wires go to one of the tail lights?

Where do the wires route through?

How much wire do I need to redo this?

Thanks,

Jed

Also, does anyone know what these random wires at the front of the trailer go to?

[mary and bob]

I completely rewired our Uhaul. I found that some of the original wiring was dry rotted and split open under the trailer exposing bare wire. The way your trailer is wired is you have those two wire cords that go into the tongue. They come out the tongue under the trailer. One cord goes to the right side (curb or door side) and up through the floor about under the closet/furnace area. The other cord that comes out of the tongue under the trailer goes up through the floor under the sink. Left cord goes to left tail light and some of the marker lights, right cord goes to right tail light and the rest of the marker lights. I don't remember what marker lights were connected to each cord, doesn't really matter. I believe it is wired this way with the two cords so that when the trailers were rented they would tap into each tail light on the tow vehicle. Uhaul had replacement bulbs that had wires coming off them for this purpose. I have a set of them. What I did with my rewire job is this: Ran new 4 wire flat trailer wire along the tongue not in it, up through the floor on the right side, back to the right tail light. I am only using the red lens part of the tail light. Made my connections at that light, ran wire from the right light, across the rear inside of the trailer over to the left light, made my connections at that light. The marker light wires come down from between the walls, on the left & right sides, about where the original cords came up through the floor. I spliced into the tail light and ground wires at each tail light with a two wire jacketed wire harness and ran that forward to tap into the existing marker wires that hang down between the inner & outer walls. If you want to also use the amber part of the tail lights there is a converter that will allow you to do that. I'm assuming in all this that your tow vehicle has the 4 wire flat plug?? I have a rear mounted bike rack, so I put an extra set of stop/turn/tail lights on it that is powered by a completely separate wire harness that is tapped into the plug at the hitch.

[felix2]

I ripped all the wiring out of my Burro 13 and started from scratch. I can post the wiring diagram tonight for you if you'd like. It's pretty straightforward as long as you aren't tying the running lights into anything but the tow vehicle 4-pin connector.

My 4-wire runs along the tongue and comes up ito the driver's side front cubby, then routes under the galley to the rear cubbies where the rear lights are picked up.

I rewired all the outlets and lights separately, connecting them to an inverter/charger. The second set of wires you have might connect this system to the tow vehicle for charging while driving?

[Jederick]

The trailer had a round six plug on it and my truck had never been set up for towing before so I put a round six plug connector on it. The whole thing has been causing me a ton of headaches! I'm new to this trailer wiring so I'm slowly figuring it out.

If I want to use the amber part of the tail light as turn signals I need a converter?

Felix if you could post your diagram that would be great!

Hopefully I can get this figured out!

[djtriceflt]

Originally Posted by Jederick

The trailer had a round six plug on it and my truck had never been set up for towing before so I put a round six plug connector on it. The whole thing has been causing me a ton of headaches! I'm new to this trailer wiring so I'm slowly figuring it out.

If I want to use the amber part of the tail light as turn signals I need a converter?

Felix if you could post your diagram that would be great!

Hopefully I can get this figured out!

Mr.Jederick,
Just to let you know there is hope! Many of us have had similar issues and we resolved them. Some, like Mr. Bob and others have totally rewired their trailers. I personally did not do that and found my original wiring in good shape, not needing replacement. I did initially find some bad grounds that was causing my intermittent faults. I wanted to have the upper amber tail lights operating as turn signals and found the only way to do it is with a converter, as you said. The converter changes the TV two way signal to a 3 way signal giving the extra signal for the upper taillight circuit. I also decided to use a 7 way round plug which gives several extra circuits like enroute battery charging, backup lights, etc. On pages 4-7 in the Parts manual the DC and AC circuits are depicted : Fiberglass RV - Document Center - U-HaulPartsManual
Those schematics along with a voltmeter/circuit tester, new connectors, soldering gun (I stay away from crimped connections) and some heat shrink tubing put my original wiring back in shape. Oh, I forgot to mention some patience with head scratching until I finally found those ground faults!! Hope you get it resolved soon so you can enjoy your UHaul!

[mary and bob]

Here's another idea; as I recall the original Uhaul wiring color code was black wire was ground and white wire was the power or positive wire. Normal trailer wiring the color code is opposite, where the white wire is used as the ground. Maybe your tow vehicle plug is not wired compatible with the trailer plug, causing a direct short. Another odd thing is that the amber part of the tail light has a double filament bulb, but only one filament is used as the directional light, the other wire is not connected. Apparently this was done for standardization reasons, both bulbs & sockets the same.

[keekers]

Welcome to this forum Jed. Lot's of brains to pick here and people always willing to help. Yeah, more UHaul's.
Patti

[felix2]

Here's the wiring diagram for the 12V running lights! Pretty easy, once you look at it.

[Chris Jones]

From U Haul the white is running lights, the black is turn signals, and the green would be the turn signals for a vehicle with lights wired for different turn and brake lights. Not for a 4 way flat. If it was converted to use a 4 way flat the green is then tied to the ground. I sent you a PM so you could give me a call.