I have an inline aluminum trailer and the running light just quit working. Checked the truck - power coming back to 7 plug connection good. Brake lights work. I know how to troubleshoot lights, but have a major issue. the cord for the lights going into the aluminum tubing right away and I can't check anything without taking the trailer apart (rivets, paneling, etc). Any ideas on what to do here? Thinking of starting all over with another set of lights. PIA at the least. Can't think I am the first one to deal with this.
Trailer Light Issues
- Thread starter sjb
- Start date
groomerdriver
New member
Just an idea......run a separate ground strap from the trailer to the truck then recheck. This will eliminate the ground as being the problem.
groomerdriver
New member
Yup.....makes sense. But just to make sure? Effin' grounds seem to be the root of so many problems. Just throwing it out there to cover all the bases before he rips out the wiring and finds that a critter bit thru a wire.
skidoodoug
Member
On my trailer anyway, the turn signal/brake lights are separate wires than running lights. I had BL/TS but no running lights on left side. It was a broken wire at the plug. Maybe it came loose there??
I know it would be alot of wire, but at times I had to run jumpers to determine if a wire is broken internally.
Please let us know what you find.
I know it would be alot of wire, but at times I had to run jumpers to determine if a wire is broken internally.
Please let us know what you find.
I borrowed an enclosed trailer this winter that had some running lights that didn't work. I found that the running lights didn't have separate ground wires. It was using the body as the ground and there wasn't a good connection anymore. Removed the lights. cleaned up the ground that they work again.
snowfish
Member
Yep, electricity can do funny things. Have seen this many times. 99.9% of the time it's a grounding issue.
With your running lights on, even though they do not work on the trailer, do the turn signals still work the same?
Or with the running lights off, turn signals on, can you see the trailer clearance lights just slightly pulsing?
If so, 100% chance it's the ground wire. Either on the trailer, tow vehicle, or both.
Aluminum and steel don't like each other. A steel fastener, holding a steel ground wire end, will corrode between the surfaces, and ground will be lost. May Look OK, but still not be making contact.
Jumper cables, from trailer to tow vehicle, should tell the story. Thanks for keeping us posted.
I have fought many grounding issues in the past having owned more trailers than I care to think of. What makes this more of a challenge is the wiring going through the frame. Great idea until you have an issue, right? There is zero indication of light on the running lights. I know what you are talking about regarding the light pulse. The brake/turn lights work like they have always done. All lights are LED's, but don't think that makes a difference. Probably actually better, they will run on very low voltage even if there is an issue.
I believe my lights have a pig tail attachment at the back end. So I pull the lights apart there and test with a gel cell. Then I know for sure it is the wiring. Just don't know what I will do about it. Ugh...
if you can remove each light and look at the wiring as far back at each light location as possible (usually there is a little extra wire shoved in for each light location) to make sure everything looks good, including you license plate light. I few years ago my lights all went out and it ended up being a bad manufacture butt splice. Easy fix but a pain to figure out. good luck!
You might have something here! I installed a new battery and the lights came on the trailer without being hooked up to the truck. Didn't think anything of it - but maybe you are on the right path. That is the only change I made and now they don't work.
groomerdriver
New member
are the bulbs good??you checked them with an ohm meter correct?replace the bulb and measure continuity of the running light circuit to ground(find running light circuit on7 pin of trailer and read to ground)If it shows a value it's good if it shows open there's a problem, check the connectors,crimp on's are notorious for corroding the wire away just inside the insulation
snowfish
Member
jmvette427
Active member
Bingo: it wasn't broke till you f##cked with it! LOL
Well boys and girls, we are not done yet. Man I wish I had a nice warm shed to work in. When it is 50 out, I don't have these issues.
Anyway, checked the connection at the brake away. took the sheathing apart. All looks good, or at least pretty good. Tracked the wires back and with a 12 volt gel cell and jumper wires, checked the lights. They all work fine. I don't wire trailers, but they are all ran in series, so if one is bad, they all will be bad, right? So I went to the first one and can get them all to light up. Again, indicating a bad wire from the trucks pigtail to the 1st set of wires.
Any other thoughts?
Must be no snow with all the feedback on such a lame issue.
Thanks for you help.
Anyway, checked the connection at the brake away. took the sheathing apart. All looks good, or at least pretty good. Tracked the wires back and with a 12 volt gel cell and jumper wires, checked the lights. They all work fine. I don't wire trailers, but they are all ran in series, so if one is bad, they all will be bad, right? So I went to the first one and can get them all to light up. Again, indicating a bad wire from the trucks pigtail to the 1st set of wires.
Any other thoughts?
Must be no snow with all the feedback on such a lame issue.
Thanks for you help.