LED power issue

[kai38]

I bought a trailer with pre wired LED ceiling lights.
I installed a battery up front in battery box ran a ground to frame
Ran power through frame into rear of trailer to fuse panel
I also ran ground from fuse panel to frame.

I hooked pre wired LED ceiling lights to fuse panel and lights are very dim, so dim you could not read a book from light emitted from them
I replace one LED light pod with a different one that I know is bright, its still dim

I put a meter to my +/- coming into panel 12.6
Same at power going to lights 12.6, but......
At the LEDs it's only 7.59v
If I take the leds straight to power they are very bright.

Whats wrong?
I went back and scraped the paint on the frame at the ground and no improvement.
Any ideas where to look next?
Thanks

 

[Ducky's Dad]

Reversed polarity somewhere?

 

[336]

If it were me, on a trailer I would drag a ground loop and not rely on the chassis for the ground.

Use a temporary ground test wire keeping everything else as is and see if that helps,

 

[Martyn]

It's not reverse polarity, LED's don't work it the leads are switched.

Sounds like something is faulty with the pre wired trailer, either the wrong gauge wire or something physically wrong with the wire or a connector.

Might be easiest to re wire the lights. Pull both positive and negative wires, don't rely on the chassis for a ground. You should run positive and negative wires all the way from the battery.

 

[kai38]

While troubleshooting the problem a wire came completely loose, and I've lost power to 4 out of 6 lights, the wires are up inside the ceiling and i won't be able to pull new wires because of the insulation.
Now I need to figure out how to rewire new lights and hide the wiring.
Not very happy tonight

 

[patoz]

From the diagnosis you have posted, it sounds to me like you have a bad connection between the fuse panel and the LEDs themselves. It could be in the positive leads between the common point where they all tie together and the fuse panel, or it could be on the ground side of the lights.

A bad, (aka loose, or corroded) connection can pass enough voltage to read 12VDC, but due to the resistance present in the connection, not enough amperage to do the job. The supply lead (or the ground wire) could also have been damaged in the construction process and is passing just enough current to read the 12VDC, but not enough amperage. It would be similar to running a 22ga. wire to your big old school Halogen off-road lights, when it should have been 10ga. You can use a long 12-14ga. bypass lead from the battery terminals and check each one separately working your way back from the lights until you find the problem.

Depending on what brand of trailer you purchased, sometimes installers use the cheapest quality components they can get away with. I have even seen wire nuts used for this application, which is an absolute No-No! Wire nuts are subject to failure due to vibration and movement, and are totally unsuitable. A good quality tin coated crimp connector with adhesive heat shrink covering should be used for the best service. Or, you can solder and then cover the connections with the same kind of heat shrink.

This kind of problems can be flustrating and hard to find sometimes, but it usually turns out to be something simple.

Good luck...


Edit: Apparently, I didn't see your update before I posted, but I'm going to leave it for anyone else who may experience the same kind of problem.