Trailer warning, this could happen to you

   / Trailer warning, this could happen to you #61  
I fill them with silicone when I put them back together.
If you are using RTV, make sure that it is electrical grade. Normal RTV produces acetic acid as it cures, and I've seen wires and connections fully corroded from the RTV... a clear case of the "cure" being worse than the problem you were trying to prevent.
 
   / Trailer warning, this could happen to you #62  
A bit of hot melt glue works great on electrical connections. Use it to seal connections on the trailer.
 
   / Trailer warning, this could happen to you #63  
Go down and get you a 7 pin replacement plug and open it up and check how it's labeled. Then wire it based on the color code provided by E-trailer. You'll get a rude awakening when you test it out.

That color code you posted on that diagram from E-trailer is wrong

Plug placement might be correct. But you will encounter a huge gremlin since about 90% of the replacement 7 pin rv plugs are labeled for color.

Occasionally I'll have one labeled for use.

I don't know man.... I've only had 18 years replacing those plugs multiple times a week
I recently purchased a new to me, travel trailer made by Arctic Fox that needed a new 7pin plug. I pulled one out of my 12v electrical box along with a diagram on wiring it that I've used several times, but more than 15 years ago. It did not match the OEM plug on the trailer. I duplicated the OEM wiring and all works fine on my 2024 F350 as does the plug I put on my box trailer 15 years ago. I don't understand!!!
 
   / Trailer warning, this could happen to you #64  
I don't get too hung up on the wire colors. They can vary from trailer to trailer.

Where it can get tricky is when going from commercial 7-pin round to 7 flat, and that's because the brake and turn signals are separated on the commercial side.
 
   / Trailer warning, this could happen to you #65  
I don't get too hung up on the wire colors. They can vary from trailer to trailer.

Where it can get tricky is when going from commercial 7-pin round to 7 flat, and that's because the brake and turn signals are separated on the commercial side.
I have a Ranger trailer light tester box at work that handles everything but the commercial trailer.

It's set up for the 7 pin rv plug, plus it came with the adapter that does 6 round, and 4 or 5 flat.

I pinned out and changed one side of a 6ft semi trailer cable to the 7 pin rv plug.

This way I can use my box to test our semi trailers at work.

I combined the side lights and back marker lights to work off the marker light circuit on the box.

Turn signals are hooked to the corresponding turn signal on the box.

And wired the brake lights to the trailer brake circuit on the box since automotive brake lights and turn signals use the same bulb on trailers.

It's also saved me and my employees some time if we have a third party hauler complaining that the trailer lights don't work. We can easily determine if it's a trailer wiring issue, or if it's the third parties truck thats the issue.

I just have to remind my employees that the brake lights on a semi trailer are triggered by the trailer brake circuit on my test box.
 
   / Trailer warning, this could happen to you #66  
   / Trailer warning, this could happen to you #69  
I often use hot-melt glue to seal/protect electrical connections. Any opinions or experience from others with this, good or bad?

Never thought of hot glue. For exterior connections I use a liquid electrical tape followed by heat shrink tubing.
 
   / Trailer warning, this could happen to you
  • Thread Starter
#70  
I’ll tell you this, ever since I found and removed the tiny screw, no more wacky trailer brakes.
That could have been a disaster. Once you slide back the cover and look at the guts of your trailer plug, you can see how easily this could happen.

I was thinking of using Loctite.
 

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