Tail / brake / marker lights not working

[Nerds 2 You]

Hello all, I just purchased a 2007 Jay Feather LGT 29N and got a great deal on it because it has a few issues. One of the issues is that none of the lights required for towing work, the previous owners said they used to see a squirrel hide in there years ago and the lights didn't work after that. This trailer has not been taken off their properly since about 2014 so they never worried about it.

The connector was corroded so I put a new one on in hopes that it was that simple but it is not. I thought I would be able to get under the unit and find where the wires may be broken, unfortunately the underbelly is completely enclosed.

There is power going to the battery when it's plugged in to my Explorer (factory tow package) but I wasn't able to check if the brakes are working.

I removed the tail lights from the bumper and looked in there and all wires I could see are intact and get no voltage from my meter.

Has anyone removed the underbelly to get to the wiring? Where is the junction box (it's not in the front storage bin)?

Any help or advice would be greatly appreciated.

[Jagiven]

Welcome Aboard!

Being none of the lights work, tells me it is a grounding issue. That is the only thing that is 100% common to all the lights. Now with that said, if a squirrel chewed in just the right area, he could have hit all the wires at once.

Do you have a multimeter? If not you really want to get one!

Start off by checking continuity between the 7 pin ground slot and the TT frame. I suspect you will not have continuity. Follow the 7 pin wire harness back to the main junction box. Most likely it will be a standard metal J-Box (not weather tight). Open it up, check ground. Then work your way back to where the ground wire connects to the TT frame. I suspect you will find a corroded wire connection at the TT frame. If you can not access the ground point due to the Coroplast you can easy create a new ground point on the TT frame. On my TT, Jayco followed the wire colors on the attached image to all my lights.

[Nerds 2 You]

I checked and there is continuity to ground. and checked that there is no voltage going to the tail lights at all by connecting my meter to ground and testing the + terminals on tall the lights in the bumper

[Nerds 2 You]

I was able to solve my issues and will post my findings if anyone else has a similar issue.

I was able to find the junction box under the trailer about 2 feet from the front of the trailer on the drivers side. There is a square cut out of the bottom belly cover with a panel made of the same material as the belly cover which is being held in by 4 screws.

I removed the panel and found a square electrical junction box, same type you would find in household wiring. There are a lot wires in the box are all connected using wire nuts which is probably not the most reliable way to do it. I reached in and moved some of the wires around and the tail and marker lights started working, but I still had no brake lights. I hooked up to my Explorer and puled it around the property to verify that the electric brakes on the trailer work but no brake or turn lights.

I removed the tail lights and no voltage at all to the brake / turn wires on either side, there is voltage at the connector to the vehicle though. I removed al the under belly screws from the wheels back on the drivers side, found the correct wires and tested again, no voltage to the brake / turns.

The wires for the tow lights are in a loom that was combined with other 12v wires that went into the opening that led up to the fuse box so it was hard to locate and took a bit of time tracing the wires from the back bumper to where I could access them and trace them back. There is a group of spade connectors directly below the hole that leads up to the fuse box and that is the wires that goes to the rear bumper.

I opened up the junction box again, twisted all the wire nuts to all the connections in the box and tested again.

I pulled out the tail lights again and tested, I now have voltage to the tail lights an brake / turn signals but no brake or turn lights on all 4.

I determined that the brake / turn bulb on all 4 was burned out so I replaced all 4 with LED units and everything is now working properly.

It was a bit of work but it payed off and now have really kewl LED lights with sequential turn signals that indicate which way I am turning.

I hope this helps out if you are having a similar issue.

[67L48]

That's a great story and I'm glad you got it figured out. Electrical problems are the worst because so many weird, seemingly-impossible things can start happening. And the wire runs are so long and complex that it's super hard to trace and diagnose.

You also proved that, while a pain, you can drop the enclosed underbelly. I don't know how every trailer works, but my Forest River Rockwood trailer used a series of screws through the frame + a screw-down clamp at the rear. That clamp on my trailer eventually gave up the belly (the cloroplast was cut about 0.5" too short). But this allowed me to see how it was set in place. If I had to drop it, I expect it would have taken me about an hour crawling around unscrewing the 20+ screws and working the plastic out. But, it's doable to those who feel like they need to drop the underbelly for any reason.

Again, well done and thanks for the detailed write up to help everyone else. Man do I hate it when people respond to their own thread with a brief, "Never mind, I figured it out." What? How? What was the solution?!