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Is there a standard wiring color for trailers?

PostPosted: Mon Apr 23, 2018 3:43 am
by phoenixbound
Trying to track down an issue with my taillights and clearance lights and it got me wondering if there is a standard wiring for manufactured trailers. I mean the wiring colors. It would help a lot if I knew which wire I need to be checking. In the process of trimming out the interior I have disrupted a wire somewhere and my taillights and clearance lights are not working. Thank you.

Re: Is there a standard wiring color for trailers?

PostPosted: Mon Apr 23, 2018 4:25 am
by ris
Sorry to here you messed up your wires. I kept checking my trailer lights as I was doing the trim as I feared I would put a nail or screw through one of the trailer lights. They used about 3 colors of wire on our trailer. We replaced all the clamp wire connectors with butt joint connectors that had shrink wrap ends with glue in the shrink wrap of the connectors. We also replaced some of the wires. For some reason they ran a wire from the driver side front, top light all the way to the driver side rear light at the top. We removed this 16 ft. of wire and from the rear back light, ran a 10 inch wire to this same light. Hope you figure a way to fix without messing up too much of your trim.

Richard

Re: Is there a standard wiring color for trailers?

PostPosted: Mon Apr 23, 2018 6:21 am
by Dano-Mich
Good source for wiring diagrams - etrailer.com
https://www.etrailer.com/faq-wiring.aspx

Re: Is there a standard wiring color for trailers?

PostPosted: Mon Apr 23, 2018 7:27 am
by phoenixbound
Thanks the link is helpful. I am pretty sure this is my wiring scheme, however I am trying to validate with the folks I bought it from. It is frustrating. I need to fix this before I move on to a whole bunch of other things to get ready for my next trip. My plan is to work front to back, checking to make sure I have power from the tow vehicle, then from the connector box on the trailer, etc. I was hoping it was a fuse on my truck, but after checking, don't think so. The quest continues.

Re: Is there a standard wiring color for trailers?

PostPosted: Mon Apr 23, 2018 9:02 am
by flboy
You could fuse a line from the battery and probe the lines (not ground) to trace the lines; however, your tow vehicle should have the standard colors and the pins identified. Regardless of the trailer, you can just see where they connect and know the function.



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Re: Is there a standard wiring color for trailers?

PostPosted: Mon Apr 23, 2018 10:07 am
by troubleScottie
To your original question, there is no standard.

The most common 4 wire cabling has specific colors and assignments. However, there is no requirement to follow this. As stated above, e-trailer has a nice typical assignment diagram.

Generally you need to start at the 4/5/6/7 pin connector and confirm the connection to each light and each function in light eg stop, turn, running.

There are lots of failure modes -- especially when you do not know the exact path of the wiring. Breaking the ground will fail all the lights. Some connections are daisy chained. Ground is often to the trailer frame/typically the white wire.

A simple assumption is the manufacturer is trying to save money and using the shortest possible route/length of wire. So running the wire from front to back along one edge near/on/in the frame, then across the rear to get the other side's lights. Not sure how the other side's clearance light might be powered.

Re: Is there a standard wiring color for trailers?

PostPosted: Mon Apr 23, 2018 10:35 am
by John61CT
There are standards but unfortunately not a single one.

For my DIY wiring runs, I adapt ABYC to match my boat.

Individual equipment usually has just black and red wiring.

I prefer yellow for DC negative return, not to confuse with AC's real grounding.

dark blue for lighting circuits & instruments positive

More:

https://www.boatingmag.com/sites/boatin ... k=5TZ_QJpU

Re: Is there a standard wiring color for trailers?

PostPosted: Wed Apr 25, 2018 3:36 pm
by phoenixbound
ris wrote:Sorry to here you messed up your wires. I kept checking my trailer lights as I was doing the trim as I feared I would put a nail or screw through one of the trailer lights. They used about 3 colors of wire on our trailer. We replaced all the clamp wire connectors with butt joint connectors that had shrink wrap ends with glue in the shrink wrap of the connectors. We also replaced some of the wires. For some reason they ran a wire from the driver side front, top light all the way to the driver side rear light at the top. We removed this 16 ft. of wire and from the rear back light, ran a 10 inch wire to this same light. Hope you figure a way to fix without messing up too much of your trim.

Richard

Definitely my plan going forward as soon as I get the issue resolved. I have much work to do on the inside yet and I will be checking as I go.

Re: Is there a standard wiring color for trailers?

PostPosted: Thu Apr 26, 2018 9:45 am
by hankaye
phoenixbound, Howdy;

Generally I try to stay out of electrical conversations, but I thought there may be a standard
so I went to Google and found that there is a Basic, and that is the same as mentioned above
by Dano-Mich. Now that applies mostly to external wiring (?), and the interior wiring that your
CT's manufacturer uses is pretty much up to them (?).
Here's the result of what I found ...
https://www.google.com/search?q=RV+wire ... 17&bih=718

hank

Re: Is there a standard wiring color for trailers?

PostPosted: Thu Apr 26, 2018 9:53 am
by Socal Tom
phoenixbound wrote:Trying to track down an issue with my taillights and clearance lights and it got me wondering if there is a standard wiring for manufactured trailers. I mean the wiring colors. It would help a lot if I knew which wire I need to be checking. In the process of trimming out the interior I have disrupted a wire somewhere and my taillights and clearance lights are not working. Thank you.

9 out of 10 times, weird issues with tail lights are due to poor ground between the vehicle and the trailer. All kinds of weird stuff can happen.
Tom

Re: Is there a standard wiring color for trailers?

PostPosted: Sun Apr 29, 2018 3:53 am
by phoenixbound
Update on this issue. Turned out to be a fuse on my truck. It's all good now. The build continues.

Re: Is there a standard wiring color for trailers?

PostPosted: Sun Apr 29, 2018 7:31 am
by McDave
Glad you tracked it down. Here is an information page on trailer wiring. It covers color codes and connectors as well as wire size. Also some troubleshooting basics. Could come in handy, print a copy and keep in the trailer.
https://www.etrailer.com/faq-wiring.aspx
Good Luck

McDave

Re: Is there a standard wiring color for trailers?

PostPosted: Tue May 01, 2018 7:23 am
by phoenixbound
Thanks I was looking at that diagram when I was working with it. My wire colors do not match, but I was able to track it down eventually though. I will be triple checking before I button everything up again. I have to have it ready for Sturgis and there is a million things I want to have done on it before we go.

McDave wrote:Glad you tracked it down. Here is an information page on trailer wiring. It covers color codes and connectors as well as wire size. Also some troubleshooting basics. Could come in handy, print a copy and keep in the trailer.
https://www.etrailer.com/faq-wiring.aspx
Good Luck

McDave