Trailer Lights Wiring

[CabezaBlanca]

I've seen a couple of threads recently on trailer lights not working and thought I'd do a little thread to offer some help. These are things that I use/do on trailers when I wire them up. I'm sure there are different or better ways but these work for me. If it helps one person then great. Feel free to offer what works for you.

Trailer lights are very simple. They need two things, a 12 VDC+ source and a good ground. That ground needs to tie, in some way, all the way back to the source. i.e. the negative terminal on your battery. Without one or the other the light will not work.

Do not use things. You are begging for trouble shooting nightmares if you do. I use regular butt splices to splice wires together.



A good set of crimpers is a must. Throw these in the trash or give them to your kid to play with.



Buy a crimper that resembles this. They put a much better crimp on a terminal.



This is the ground lug that usually comes on a trailer light. You can use it if you want to but when attaching it to the trailer make sure there is clean bare metal under it. After attaching it you can hit with a some spray paint to seal it up.



More to come.

[CabezaBlanca]

A lot of people like to take a separate ground to each light and not use the trailer frame as a ground path. I've done it both ways. You can use one of these or a 1/4'' bolt through the frame to use as a grounding stud works good to. Drill and tap a hole for the bolt if you go that route.



I use ring terminals inside the 7 way plugs. Just inserting the wire into that chicken **** compression fitting is asking for a headache down the road.



Here are some wiring diagrams for reference.




Obviously the best wire connections are soldered and heat shrunk. I do not have time for all that. I use regular old butt connectors with a good set of crimpers and I do not tape them up. I believe moisture gets in the tape and corrodes the connection. Without the tape moisture can get in but it can also dry out because air is getting to it. I never have issues doing this. Good wire connections and good grounds make for great trailer lights that work every time they get plugged in.

[CabezaBlanca]

And for the times you do have issues you can find the problem with one of these in short order.

[Traildust]

JKbow turned me on to these. Game changer!

[ame="https://www.youtube.com/watch?v=7Wh5gM8GM70"]Heat Shrink Self-Solder Butt Splice Connectors - YouTube[/ame]

[CabezaBlanca]

[QUOTE=Traildust;14731935]JKbow turned me on to these. Game changer!

Game changer for sure!

[sahunter]

tagged

[StrayDog]

After saying every bad word known to man and inventing many new ones, my electrician brother told me to buy those very crimpers and corresponding butt splice connectors.

One of the best tools I’ve ever bought.

[Rick]

use solder and heat shrink for connections when u can, waayyyyyyy better than crimp terminals

I have not used the ones traildust posted, but I have been wanting to buy some

[CabezaBlanca]

After saying every bad word known to man and inventing many new ones, my electrician brother told me to buy those very crimpers and corresponding butt splice connectors.

One of the best tools I’ve ever bought.

They flat out work and are worth their weight in gold!

[thegrouse]

I use the solder heat seal connectors and no zip ties to secure the wires. I use wire loom and wire clamps screwed to the frame. Learn how to use a multimeter and you are in business

[pervis]

Video sold me. Thanks again tbh. More money flushed. This website has cost me hundreds of thousands at this point....smh

[Gummi Bear]

A bunch of good info here. Thanks for sharing, it'll help a lot of folks out.

I actually keep a small book in my truck as a reference with the trailer connector wiring, and trailer light wiring. Sometimes, I have a brain fart, and it comes in handy. I printed them up years ago, and laminated them. Keep them stuffed either under a seat, or in the seat pocket.

I'm a big fan of these - https://www.delcity.net/store/Heat-S...05404.h_801795

I got a sample pack as a promotional deal from a vendor a while back, really like them.

Definitely approve of the ratcheting crimpers, they are far superior to the cheapies. I have a small collection of different crimpers that have amassed over the years as an electrician. I love my Kleins.


Gotta be honest, I've wired up many a trailer using wire nuts. My stock trailer is done up with them now. There is a huge difference between the cheap pieces of junk you get a big box stores, and the 3M ones that I use.

[EarleyBird]

Good stuff

[Smokeater]

After saying every bad word known to man and inventing many new ones, my electrician brother told me to buy those very crimpers and corresponding butt splice connectors.

One of the best tools I’ve ever bought.

Tempting....but I don't know about wearing that white glove man!

Little bit of dielectric grease in/on those connections helps em live a bit longer as well, weather you seal em up or not. Extension cord is good for your front to back runs too.(might write down your color codes tho-) Protects it a bit better if your wiring goes thru the frame or other sharp edges. Conduit clamps and an old water hose works decent as well if it's all external.

[AndyMane]

I'm in the process of re-building my 16' tandem axle. Good info.