Troubleshooting New LED Tail Light Not Working When Connected To Trailer

Updated 06/12/2024 | Published 05/19/2021

Question:

I’m switching my tail lights on my trailer to LED lights when I plug-in the new LED lights one side works the other doesn’t when I hook up the other side one white doesn’t work unless I plug-in one of the old tail lights but it won’t work if I plug in the new light whichTo see if the light is working it does but it won’t want to plug it in to the harness on the trailer was the old light will.

asked by: Gerry

Expert Reply:

It sounds like based on the description you provided of the issue that one white ground wire is not working on your new LED tail lights.

I would first make sure that the connector on your new LED light that is having the issue does not have any debris in it causing the connection issue.

Next check the ground wire going to that light and make sure it is securely connected to clean corrosion free metal. Ground wires being loose can cause all sorts of havoc.

If these steps do not fix the issue just let me know and we will go into more in-depth troubleshooting.

I included a link to a helpful article on wiring for you to take a look at.

expert reply by: Samuel C

Graham S.

6/12/2024

I am having the same problem. Tried the ground I. Multiple spots and it’s still not working. Other trailers work just fine as I’ve tested them since and so do the magnetic lights. I can’t figure it out

Samuel C.

6/12/2024

@GrahamS How many lights aren't working? I'd remove the light from the trailer, and use a 12v battery to test the light. Hook the ground wire of the light to the negative terminal of the battery, and the power wire of the light to the positive terminal of the battery. If the light doesn't come on, you've got a bad light, or have the wires (power/ground) mixed up. Also did you wire them color to color? or use the included wiring diagram with the lights? They often use very weird wire colors that don't match what that color wire should actually do, so double check that as well.

Graham

6/12/2024

@SamuelC thanks! I will try all of that and get back. Appreciate the response