Run/Nav Lights Malfunction

[Jackson]

16TBS Run/Nav lights continue to fail with blown 15A TV fuse. Will work with fuse replacement for a limited time then fail. Overload or short? Need help to track the problem. Thanks.

[Merlin]

Hmmmm......

Do the TV lights continue to work?

How long is a "limited time"?

Any recent work on the camper?

Do the lights ever flicker?

A direct short from frayed or chewed wiring would blow a fuse immediately.

Not sure why there would be an overload if no recent work on the lighting.

An intermittent short from frayed or chewed wires would cause occasional blown fuse. I would start by visually inspecting the wiring you can see.

[Powder Hounds]

I had a similar problem and it ended at the 7 pin trailer plug. The original was an absolute cluster. It was brutal how it was originally connected, easy to undue the cover set screw and inspect the plug connections.

Hope you find it!

[Powder Hounds]

This was the original 7 pin LL plug from 2020.

[DavidM]

If the TV's fuse isn't blowing without the trailer connected, then the problem is between the trailer plug and the lights on the trailer. If it is intermittently blowing, then it is likely a worn insulation spot that is intermittently contacting the frame and blowing. Follow that circuit from the front to the back and look for a worn piece of cable.

David

[Jackson]

Thanks all.  Most wiring for Running lights is internal and can't imagine rodent damage. Will update as I proceed with correcting the issue. Travel is done for the winter months so I am not in a hurry, just disappointed that our rig is down after so many years of excellent service. Will look to the seven pin connector first. Seems a likely culprit. Happy trails!

Gordon

[Pinstriper]

Every place the wire goes through a hole drilled in the aluminum is a potential cut point for the insulation. Whether its the siding, the structure, the frame - it isn't like they put rubber grommets at every hole, or deburred them.

[Jackson]

This was the original 7 pin LL plug from 2020.

The seven pin TT connector is a pre-mold pressure fit assembly that does not allow easy access. On the surface looks to be in good shape. Comments? Will continue to search for the culprit..

[Jackson]

Every place the wire goes through a hole drilled in the aluminum is a potential cut point for the insulation. Whether its the siding, the structure, the frame - it isn't like they put rubber grommets at every hole, or deburred them.

Upon further investigation, it would appear that this is the case. Application of 12V DC to the TT connector illuminates the running lights without issue. I would conclude that somewhere in the wiring, the insulation has been been worn and shorts only while the TT is in motion. Finding it will require visual inspection.  How to correct this is beyond me short of re-wiring the entire rig. Lower level wiring might be accomplished, but roof top?

[Pinstriper]

It's a re-wiring project for sure.

Forget about what routes they chose - they did that for speed of manufacture and ran wires where it is no longer convenient to access now that it is assembled.

Instead, cut and pull those wires, choose your own route from point A to B, and fish the wire through. This also allows you the opportunity to debur anything you can reach, and apply a little electrician's tape at holes where it will help. Pro tip: don't use the frame for ground. Run a separate ground wire to each light all the way back to a junction box. This will reduce future problems and also isolate them to a single light.
DAMHIK

[Jackson]

Much obliged. Looks like a good winter project. Now to find a nice warm barn. 

[Merlin]

On my '15 dual axle 16TBS, the running lights wire goes from the tongue plug to the junction box under battery box area. From there, it goes in fairly obvious routes to each of the lower running lights and tail lights. The wire to the tail lights runs through the frame for a short distance on the driver side and all the way through the bumper to both lights. The upper running lights wire enters the frame and runs up inside the frame next to the rear of the slide out. It then runs in a wire chase along around the top of the camper rearward to the upper rear lights and then continues in the wire chase along the top passenger side of the camper to the front top running lights. I know all this because I had to track down a loose connection that turned out to be a bad wire clamp in the wire chase over the shower. Took forever. @Pinstriper is right that LL used convenience in running wires with no thought to serviceability. They used the unreliable clamp type connectors and did not grommet or clean up the frame holes for the DC wiring. Somewhere along the way, you'll find wire with cut or worn insulation that shorts out, most likely in a spot where a wire enters/exits the frame.

[Jackson]

My hope, slim at best, is that I find the short at the frame level where it is most exposed. As to the upper wiring I am clueless as to how to even access it. Your advise on that would be most appreciated.

I have yet to look to the junction box under the tongue. Seeing that it is exposed to the weather and road grime as well as physical forces I will have a look there as well.

Again, very much appreciate the input.

[Merlin]

With a #2 square drive you can remove at least some of the wire chase for access. It's very likely you'll find the bad insulation where the wire goes through a frame hole. If you remove running lights to check those holes, you can pry the covers off with a small flat screwdriver and then remove the lights with a #2 square drive. Seal them back up well with silicone that has an anti mold additive.

[Jackson]

Well, I'll be damned. I could have spent the next ten years inside that trailer, and as a man with my education, experience, intelligence, good looks, etc., would have never recognized that trim as an electrical chase. It is obvious that I am not qualified to do the job. !@#$%&

Thanks