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Durable polypropylene box creates a fast, easy way to connect the wires from the trailer connector to the wiring for either a 6-way or 7-way connector. Makes replacing your trailer's connector simple.
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Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
Speaker 1: Today we're taking look at a trailer wiring junction box. This is a durable polypropylene box that creates a fast, easy way to connect the wires from the trailer connector to the trailer wiring for either a six-way or a seven-way connector. It also makes replacing your trailer's connector simple, if and when needed.The electrical junction box consolidates all the wiring connections on your trailer. It mounts to a secure area on the trailer frame. Number of terminals that this one has is seven. Comes with a flat washer and nut for each post.Basically the way that you would connect your wires to the post is you would take the wire from the trailer plug, strip it back a little bit, put a ring terminal on it.
And then take the corresponding wire on the trailer, put a ring terminal on it and connect to the same post. And you'd do that for each function.It comes with the hardware kit. So in this bag is the hardware to secure the lid to the box. Also there is strain relief brackets and screws. And it has the rubber plugs.
So you have one, two, three, four, five different access areas for your wiring to feed into. Now some people, what they like to do is remove the plug completely and just have the area for the wiring to be able to pass through into the box. What I recommend doing to keep the elements out - dirt, grime, and moisture - is just to cut an area in the plug itself for the wiring to pass through.And then it has your strain relief brackets and the actual mounting areas for the strain relief brackets. What that does is that puts tension on the wiring that's passing through and reduces any type of stress or strain placed on the actual wiring. So it's nice that those are already included.We'll go over the measurements real quick.
So taking a look at the overall measurements, going edge to edge, mounting area to mounting area. This direction measures about 8 and 1/2 inches. Side to side, going this direction, is about 3 and 5/8 inches. The overall height is about 2 and 1/2 inches. The mount holes on the unit, these mounting tabs right here, these are separated on center by seven and 13/16 inches.That's going to do it for today's look at the trailer wiring junction box..
Perhaps 1 inch wider. A more robust water tight entry point and seal for the cover to base fit up.
Perfect replacement for my trailer wiring box on my C&M 3 horse slant load trailer. It was one of the easiest installs I have had. Prompt shipping and great customer service ice
Awesome piece of equipment!! EXACTLY what I was needing!! Replaced the old torn up box and this box worked perfect!! Fast shipping and great communication, as usual!! Thank you etrailer!!
The junction box provides adequate room for wiring terminations and weatherproof covering of them. The harness for transmitting power to the trailer is of robust design with LED lights indicating proper power to the various end uses. A stainless steel u-bolt was used to secure the harness to the trailer frame and thereby eliminate stress on the junction box. Stainless steel machine screws were used to attach the Breakaway Battery Box to the trailer frame. A stainless steel quick connect will be used to secure the Breakaway switch to the vehicle. The red lead supplies 12 volt power to the Breakaway battery.
Nice junction box. Used this as a junction/access point for my ‘18 Equinox flat tow setup. It houses my 5way conductors for tail lights, the Roadmaster battery charge line circuit breaker and fuse lead to my accessory +12v port that I’ll plug my Brake system into. Also added a cut off toggle switch on the charge line when not in use.
Box is average to me has enough space in it to fit everything but like most things could be made better. As in thicker plastic, seal… Not sure how long term it would last if in sun. I put it in a place on the trailer where sun and rain would get to it very much.
I just received this junction box today so I have not installed it yet. The box appears to be well made. It has all the necessary components to make a professional installation.
Just what I needed to upgrade a older t railer
Big improvement over just connecting loose wires with wire nuts. Very organized way to wire a trailer to the towing vehicle.
solved the nasty wire mess problems,, you have bolts to tie each ring terminal to...
John
2/12/2025
Sadly, it is not water proof, when mounted on a horizontal surface, it fills up with water, and corroded all of the wiring. IT MUST be hidden in a Water Tight enclosure... I like the convience of the barrier strip, but....
We used this to wire up our '74 Holiday Ramblette that we redid a year ago. It worked great to hook up all of the lights. Haven't had any problems yet!
Great for splicing tail light wires
As advertised
Perfect Fit price was right
Beside using these boxes on trailer tongues, they're also handy at the rear of trucks. Heavy duty trucks also use seven wires. Different plug, round pins. I've used similar boxes to tidy up the wiring on many big vehicles. These seem to be decent quality at a fair price. I got this one to add a trailer connection on a school bus converted to a camper. It was shipped promptly, UPS sat on it for a few days.
Chuck
1/31/2021
A year later, all is well.
High quality
Your staff is the best. And their work is second to none
Great box, works well and easy to insta ll
Perfect! Works like a champ, for years I've used plastic conduit and electrical tape, it never holds up and looks bad. This junction box made my trailer rebuilt project look professional!
Jon
7/25/2021
Great! Still water proof and working fine.
Just what I was looking for, needed to rewire my Army truck tail lights and this box fits a treat. and is the size that I can hide from the rivet counters. Thanks again and other items I have had from you in the past.
John B.
5/19/2020
Still working great!!need one for a new build coming up. Thanks E Trailer.
My trailer's stock surge brakes worked pretty well but dragged the brakes driving down hills, did not work while backing down boat ramps, and provided no backup if my vehicle brakes failed... So I got this EOH system to solve those problems.
I only test-drove the finished upgrade once but it seemed to work fine. Note that in my 2018 Ram 1500 with integrated trailer brake control, I needed to set this up as "EOH heavy" even though my boat + trailer are under 6000 lbs.
I wanted a solid, clean install, so I had a bracket made and welded to the trailer out of harm's way and above the possible high water level, even though it's all theoretically waterproof.
Other considerations:
- I was able to re-route the stock steel brake line right to the brake unit.
- I had to buy a new 7 pin trailer harness to replace the stock 5 pin one. I made a conversion harness to go from the new wiring to the stock trailer wiring.
- I locked out the original surge system by replacing its guts (master cylinder, spring, etc) with a steel bar that goes between the front and rear pins.
- I hid the breakaway switch inside the tongue and ran the new breakaway cable where the original one went.
- I safety-wired the brake reservoir cap to prevent its loss or vandalism. It just didn't seem secure to me. Easy fix!
I think it looks good and seems to work well. I expect it will last many years. I gave it only 4 stars as the brakes have some lag (1/2 second?) before I can feel them working. I was led to believe the brakes would be instantaneous and I "would not feel the trailer" (possibly like the electric brakes on my other trailers) but it's not quite that perfect. But maybe I'm being picky! I'd choose this very system again.
All new wiring on a trailer rebuild. These junction boxes make the job so much easier and faster. Now when i troubleshoot wiring issues im chasing one wire at a time. Oh and now the wiring goes in a location that works for me
This terminal strip box is well designed. It has seven studs with washers and nuts plus a very clever arrangement for getting cables into the box - two on one end and one on each of the other three sides. Each hole has a blank (closed) or holed opening to accept a cable. Pretty clever. The slots in the box fit these plastic grommets and allows either an opening or a covered slot to be used.
I mounted the box in a horizontal position on the bulkhead near the battery supply for the breakaway switch. I ran the main 7-wire cable to the bottom and spread it along the studs according to the diagram for the color scheme. I ran the cable from the trailer to the right side (where the two cable entries are located) into the upper access hole and distributed each wire to the appropriate stud. This allows any other application to access the power source such as lighting or other accessories. I used only lights, but I had to connect the power for the lights to the blue wire out of the battery box since it is the only wire with 12 vdc on it all of the time.
When the cable is hooked to a vehicle, the 12 vdc connection has 12 vdc, but when it is not connected, the 12 vdc connection is not used and shows only 1.5 vdc. This is the black wire on the battery box. The white wire is ground - between these is the power for the battery charger. The blue wire, however, has 12 vdc on it at all times, so disconnect the battery before hooking it up. And don't connect the blue wire to the blue wire of the cable from the vehicle. The blue wire must be connected to one of the wires on the breakaway switch (I used a red wire to the switch and a black wire back to the box) and the return wire is connected to the blue wire for the brakes. So when the plug is inserted in the breakaway switch, the switch is open and no power applied from the battery to the brake solenoids. When the plug is removed, the switch is actuated and 12 vdc is applied to all of the brake solenoids in parallel. The one side of the switch is hot all of the time unless the battery is disconnected.
My new towing vehicle required a longer cable so I purchased the cable below as well as this junction box to make my life easy. Installing this junction box allowed me to make some corrections based on vehicle side wire colors and trailer wire side colors which differ. I mounted it on the side of the trailer to hold it in place firmly and it works perfectly. This is a great way to have a neat installation that looks like it is completely sealed from weather and insects. Highly recommend this.
Hopkins 7-Way Blade-Style Connector w/ Molded Cable and LEDs - Trailer End - 6' - Auto Standard
This junction box was a great addition to my trailer wiring as it provided a watertight location to make up connections without splicing wire. A suggested enhancement would be stainless mounting screws to eliminate the rust potential.
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Brianb
6/17/2020
One year later and the box is still holding up strong! Great product!