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.
Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
Shane: Hi, I'm Shane with etrailer.com. Today, we're going to be going over the junction box for trailer wiring. This box is going to be a polypropylene box, very durable plastic. It's made to be mounted on the frame of your trailer. And what this does, this allows you to wire your 7-pole plug separate from your trailer wiring. So, say we have our 7-pole wiring, it comes loose, drags the ground, or gets damaged.
We're not going to have to cut it off of our wiring coming from our trailer in order to replace the plug. We can simply take it off of the pegs here, replace our plug, and add new ring terminals, stick it right back in the box and connect it directly to our wiring.And with a trailer this size, or larger trailers, if you maybe want to add a breakaway switch, it's very easy to run that wire over and connect it directly on to the brake wire coming off the 7-pole plug, without having to cut the wire coming out of there and splice them together. Depending on how your trailer is set up and how your 7-pole plug wiring is done, it's going to have to be tested. Your box is going to come with a sheet inside, it's going to look like this, on how it has to be set up.However, this is not always accurate with the plug itself. If you have the 7-pole plug, it may be wired just a little bit different than this.
Trailer wiring needs to match whatever the functions are coming off of your 7-pole plug coming from the vehicle. You're going to have a power wire coming in. You're also going to have ground. The ground coming off the center post needs to be grounded to the frame. So you're not only grounding the 7-pole plug, but you're also grounding this setup here on the box.The box is going to come with five rubber knockouts.
You can either cut these or they will also come with another set that already has a hole already open. I, myself, just like to cut an X in it and run my wires through it, it kind of helps it seal a little bit better. These will seal underneath the lid. Each place that your wire comes in, you're also going to have a metal clamp with two screws, and that's to hold your wiring in place to keep it from coming out. The lid you can see here, it's got a groove, and what that does is it seals around this edge to keep any water or anything like that out.It's going to come with two large screws to hold your lid in place.
Again, I'm Shane with etrailer.com. That's going to do it for our look at the trailer wiring junction box..
Average Customer Rating: 4.7 out of 5 stars (115 Customer Reviews)
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.
I use these all the trailers here. The polypropylene stands up much better to sun, weather, and bumps than the ABS versions. Makes it real easy to change out the trailer plug when they inevitably get damaged.
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.
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!!
BrianB - 06/17/2020Used when replacing connector and breakaway switch on my enclosed trailer. Was easy to use and install.
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 H - 07/25/2021well made, attention to details with grommet sizes.
Rick - 05/23/2022These make it so much easier to troubleshoot trailer wiring and are a really clean solution.
etailer gets them to you faster than expected.
Great product, great price.
Very good junction box for the money. I used it to wire in a 7 pin RV and 6 pin round to vehicle.
Overall product looks good but would liked to have received mounting screws and wiring clamps that were advertised as part of the whole assembly.
Sierra K - 09/13/2021Part arrived and was a day earlier than promised. I will install it this weekend and hope my installation is as good as the product.
I think the product is exactly what I ordered and exactly what I wanted. The 1 star is for filling up my inbox with junk mail. It made me not want to do business with etrailer.com again.
so far so good, much better than the top test unit. over time the top test button would take water in and short out the board inside. this one having everything on the side works much better
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 - 01/31/2021I'm using this box as a junction point on my semi tractor. Worked like a dream for trailer wiring splitter.
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.
Great workbox for our trailer wiring pr oject.
Exactly what I was looking for, fast shipping, best price…etrailer has never failed me!
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 G - 05/19/2020Worked great for distribution of the trailer/power wires. The terminals make it easy to attach wires in an area they will not corrode. I will definitely use on the next trailer I rewire.
I actually used this on my dump truck. I mounted it back by the hitch and split all the dump wiring off with in this box. It makes for a very clean install. Makes it very easy to connect trailer wiring.
I chose this box because it was economical and I didn't need it to be water-tight because I mounted it inside my old camper. My priority was to organize a mess of wiring and to make it simple to switch the type of tow-vehicle connector. I'm very happy with the result. Those little nuts that fit on the terminal posts are 3/8 inch - so get a socket that size to help you screw them on and off (with your fingers not a wrench). And be prepared for those nuts to fall down and roll into hard-to-reach places inside the box. If you have a magnetic retrieval tool you can save some frustration.
This box makes the wiring so easy especially if you have brakes and ever need to replace the pigtail/connector to the tow vehicle. I will likely use these of other purposes they are so convenient.
Installation was a bit tricky as the wiring diagram instructions didn't quite match the truck(s) we use wiring. But figured it out and it has been working great since. Purchased it because original plug on trailer was too short and kept pulling free from trucks and dragging on ground.
I have used these before and they are great for a trailer wiring project. However, you must be careful when mounting to ensure that you do not crack the housing. If the mounting surface is not perfectly flat and/or the mounting tabs flex it will crack. i mounted two on my trailer and one cracked the other did not. A little silicone will seal it up!
Well built - exactly what I needed. Great response and quick shipping from etrailer. I have already placed another order with them.
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