I stumbled on this video after hours of trying to figure out what my issue was. In 4 minutes i was able to figure out what was wrong and fix it! Great video, thank you!
THANK YOU!!!! I have been struggling with what was wrong for a week with my wiring for new lights. Grounding the poles on the trailer was it! You saved my sanity!!
Super helpful. Most helpful RU-vid video I've seen regarding this issue. I assembled a Harbor Freight Haul Master 4 x 8 folding Utility Trailer last weekend and the lights they packaged had a separate ground wire for each light while the instructions assumed I had been sent self grounding lights. There was also no screw hole on the tongue for that ground wire which the instructions indicated there was. My first time wiring up a trailer and this video has given me confidence to just roll with the lights I have and ground each one to the frame of the trailer. Seems to me that having a grounding wire for each light might be safer in the long terms than having self grounding lights anyway(?).
Wow! 4 1/2 years later this is still the best video out on youtube. I have a folding trailer and had no idea that could cause my grounding problem. thanks for putting that in your video.
This is me right now. I wanted to do a quick test with it folded up after installing some new lights. Brake and turns worked fine but not running lights. Hopefully it's just the grounding issue while it's folded. Will try again with it unfolded to see if it's all working.
Update: It wasn't just the folding. The running lights still don't work, so I think it's an issue with the vehicle wiring. I'll have to take a closer look at that.
Can't thank you enough for the video. I have a folding trailer and spent more time than I'd like to admit trying to get the lights to work. Your video helped me solve the problem! Thanks
Best video I've seen on RU-vid about this issue... You're an excellent teacher. All the info you provided was succinct, therefore easy to understand. I feel confident I'll be able to troubleshoot and fix the malfunctioning lights on my trailer. 👍
I've spent far too much time troubleshooting my "sometimes they work fine, other times not" touchy boat trailer lights. Never before had I been told about the light ground via the bolts. I scraped off the paint around the holes where those attachment bolts fit, and problem solved! Same as Scott below. Thank-you.
Excellent video! Just this past weekend we assembled a kit trailer from Norther Tool. It came pre-painted in black and of course all of the holes are painted as well. None of the lights work and I've already determined that there is power to the connection on the back of the tow vehicle. Time to do some sanding and reconnecting the ground wires! Thanks!
Same! No one is talking about how to ground everything properly! It's like everyone assumes you know what you're doing, which is so stupid because this is why we're looking for help - because we don't know what we're doing!
This video saved me a bunch of time. Grounding issue at the light. It was driving my crazy trying to fix it. Just had to clean the bolts and reattach the light and back in business!
Excellent video thanks, solved my lighting issue on a new trailer, i had the lights that ground through the bolts and the paint was blocking the connection, after cleaning the metal and reinstalling all works perfectly now.
Fighting with my trailer lights for about two hours today. At my whits end, finally decided to give RU-vid a try. Thankfully I found your video and fixed my problem in short order.
Awesome video! Helped a bunch. Didn’t realize that the tail lights without the ground wire uses the bolts as the ground. Cleaned where the bolts contact the trailer, problem fixed. This is also a tilt trailer I’m working on and if you shook the trailer the lights would go in and out. Put a ground wire where it tilts. No flickering of the lights. Thanks for your help!
Follow the rust. A month ago I had a truck bed to frame rail, that connects the 2 because the bed mount rubber isolates the bed, completely gone. I fixed it (added 2 clips and braided brass wire to connect them, ground down to bare metal first, clipped the braid to the 2 bare spots) and the trailer brakes worked again on my dump trailer. This week, no brakes again, ended up being on the trailer ground, where the run away trailer cable box grounds, sharing a bolt with the ground that comes up from the wire bundle for all the trailer's lights and brakes. I ground all fresh metal and then coated around the edges, leaving bare metal and used a new bolt to tighten it all and used more di-electric grease to coat it. Should be good for a few months, then re grease to try and prevent water from entering and rusting. I will put it on my calendar to pop up monthly, and I can ignore it, or eyeball it.
Yes sir this video gave some insight as to what the problem was... which I would have never thought to look for... I have a fair new 2017 F-250 that recently was having no trailer tail lights didn't know what happen was working when I got the truck, anyway watched your video and "BAM" check out the truck not the trailer by the way I ran new lights on my boat trailer...so I figured that's where the problem was.. anyway it wasn't, truck had no ground (WHAT!!!) ok grabbed my manual and looked up my fuse location and found out it was not blown but missing... problem solved! Thanks 😊
Thank you for this video, very informative. I just bought a boat trailer and I am seeing a strange problem, the lights work when I stand on the trailer, as soon as I get off the trailer the lights go out, what should I look for, please help me troubleshoot this. Each fixture has a ground wire connected to the trailer.
Will you read voltage if it isnt grounded? I read 12 v at the light, but it wont work. I tested the light separately on a battery and it works. I has the confuse...
One thing that ended up being my problem was the ball hitch. My trailer was setting for some time and the inside of the coupler was rusty and not making a good grounding connection with ball.
I have newly wired an enclosed trailer and cleaned all the grounding points and checked all the connections with a meter and I only have super dim side markers. Nothing I do changes anything. All the lights work when tested on a battery and all the pins from the truck test good. Even my LED taillight bar works perfect but the trailer lights just won't work
Tilt Trailers must be grounded on the bed not the tongue! if you ground on the tongue your going through the hinges and the lights will cut out when you drive, if you ground through the bed where the lights are bolted to, your good.
Mine signal n break light works fine but when i turn on my truck lights the ones from the trailer supposed to turn on too but they wont like i said on ly break n signal works what can i do
Everything works properly on mine except when trucks' lights are on. My brake lights go out on the trailer when I hit the brake pedal. With truck lights off everything works normally. I have the stud type of light mounted to PVC pipe and I ran wires from lights directly to the ground wire on the harness. Does anyone know how to correct this? Or what I may have done wrong?
Thank you for the video. I'm not sure this is my problem with trailer running lights, but it give me a good place to start. Does the trailer hitch need to be in contact with the truck ball in order for the lights to work on the trailer, particularly the running lights?
Why cant you run the white wire all the way to each light fixture ( if it has the separate wire) it would make for far less connection issues down the road, would it not?
Nobody answered you yet so hopefully you figured it out. Aluminum is a better conductor than steel. The problem with aluminum is dissimilar metals corrode. I would recommend cleaning aluminum and connector and apply die electric grease during assembly to prevent corrosion. He should have mentioned this as its a good idea even on steel trailers.
Also newly painted brackets that doesn't come with your lights need to be sanded down for metal to be seen for good contact each light has to be grounded if not having the white wire included! Hope this helps!
Just curious....couldn't the ground cables at the lights be mounted to one of bolts holding the light? They're going thru the frame. I am putting a set of these on right now and was wondering if this would work instead of drilling thru the trailer?
I realize its been a while so this may not actually help you any, but for others... Yes, I've done this dozens of times and as long as you have a nice clean spot to seat the eyelet it should work great. Sometimes I double nut the stud where I choose to install the eyelet, putting it between the two nuts.
I have a weird one. Just purchased a 5x8 utility trailer. Left signal, both tail lights, and brake lights are working fine. The right one blinks at normal speed exactly two times then goes to a fast blink as well as the right blinker on the truck. As soon as I disconnect the plug, truck right signal goes back to normal speed. When I connect the same truck to my boat trailer, everything works fine. Anyone have any ideas ?
So let me get this right. Old school lights don’t need a ground to operate. New LED lights need to be grounded at both the tongue and each light terminal in order to operate?
