This Spectro trailer wiring junction box provides 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.
Features:
Specs:
Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
Today were going to install part number 38656. This is a trailer wiring junction box. First thing were going to do is find the location for our junction box. Were going to go ahead and install on the inside edge of the tongue. Well go ahead and hold it up to the tongue and then well go ahead and use a drill to mark it for our holes. We have our holes marked, well go ahead and remove the box, and then go ahead and drill out our hole.
Now well go ahead install our hardware and install our box. Now were going to use a quarter inch hardware to install the box to the frame. This hardware does not come with the box. With our box installed, we can go ahead and start getting our wiring ready. Well go ahead and cut our wires to the length of what we need and then well take our excessive length from our gray cable and use the white wire for our ground lead.
Were going to take the white wire, well add a couple of ring terminals, and well go ahead and connect it to the post labeled white and ground. Well also change out one of solid grommets for a hollow ground. With our new grommet installed, well go ahead and fish our wire through, and attach it to the box, and then were going to use a self-tapping screw to attach it to the frame. Now well go ahead and get the rest of our break cable ready, the gray cable will be for our electric brakes. Well cut back the gray sheath to expose our two wires.
Our white wire will go to ground, our black wire well go ahead and post to label blue, blue is only the function for brakes. Well go ahead add some ring terminals to it, then temporally put them into position. Now well go ahead and hook up our wires for our trailer lighting, well also go ahead and run it through the grommet and then go ahead and install our ring terminals. Now the brown wire on our trailer will be even running light circuit that will go to the post labeled brown, it will also say taillights on there. The green wire will be our right turn signal, well go ahead and connect that wire to a post labeled green, and it will say right turn.
The yellow wire well be our left turn signal and that will be connected to post labeled yellow and left turn. Now these wires have been loosely installed. Next well go ahead and wire our trailer connector, this is going to be a seven molded trailer wire connector, eight foot long, part number h20046. You see the seven pole and we have our wires. Once thing to know about this is that the functions do not match the colors better on the trailer. Now on the other side of the box well go ahead and replace them with solid grommets with a hollow grommet and well go ahead and run that over our wire that we can go ahead and push the wire back into the box. Then well go ahead and add our ring terminals to our wires. Now well go ahead and start attaching our wires, well start off with the green wire from the seven-pole which will be our running lights; this will be connected to the post with the brown wire from the trailer lights. The brown wire will be our right turn so that it will be connected to the post with the green wire from the trailer lights. The red wire will be the left turn function on the seven-pole, so well connect that to the post with the yellow wire from the trailer lights. Our blue wire will be our brake control power, so well hook that up to the post labeled blue. Now our yellow wire is usually reserved for reverse light or whatever function youd like. However, this application is not being used, so well just ignore that wire. Our black wire will be our 12 volt power supply, however this trailer is not using it right now, but well keep it to the junction box for our upgrade in the future. Well now go ahead and take our white wire push it to the ground from our towing vehicle that will be transferred to the trailer and well connect that back up to the white post, well get two white wires. With all of the wires in place well go ahead and tighten down the nuts. Next well go ahead and install the clamp from the wires that come in from the trailer side. Looking at the box on the left hand side there is provision for a clamp. Well make sure everything is pushed together properly and wont get pinched, well go ahead and install the cover. Well fasten and replace of these two bolts. Thats what it takes to install our junction box. All right with that it will finish it for our install of part number 38656, a trailer line junction box on this new trailer.
Average Customer Rating: 4.8 out of 5 stars (600 Customer Reviews)
This Spectro trailer wiring junction box provides 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.This product is very easy to install and seems to be of very good quality. I like the way they designed it so it is waterproof and it came with everything you could possibly need to install it. 642028
Herb B - 05/15/2020
This product didn't do much for me. It's a minor pain to use and not much benefit. That said, there is nothing wrong with it. 442156
Doug B - 10/19/2018i have used the product and it seams to be working fine i have nothing negative to say about the product very happy 695804
I have used errailer at different times. Each time their products have been the absolute best. Their phone clerks are knowledgeable of product and service. Shipment time has always been extreamly prompt, sometimes as little as 2 days, retailer is unaware that I grew up in a fleet service shop, I owned and operated my own for 20plus years. I also have a [retail] store that uses their service, a simple ITS THE BEST is all I should say! 343776
This product is a great way to fix a spot in the wires where they dragged on the ground. I simply cut out the bad areas and attached proper size wire nuts and secured this junction box. 179837
Jason H - 03/18/2016Came in as it should have. 735748
The wiring junction box is high quality, watertite, and makes for a professional wiring of brakes and lights. I am in the process of converting all my trailers to this junction box. 132015
lwal - 05/27/2015I have ordered several products for the re-wiring and updating of by 10000 lb sailboat trailer. I have ordered electric brake kits, wire terminal boxes, led lights, etc. The shipping is incredible and fast, and the products are well made. 640109
This junction box made it very nice to hook up my trailer plug to the trailer wires rather than individually connecting them and trying to keep them sealed from the elements. It also made a much cleaner set up. The box itself is made of a rigid but flexible plastic rather than a hard plastic that tends to break. 528876
Charlie - 07/03/2019We wanted both a 7-wire and a 4-wire plug on the same trailer. This junction box made the installation very easy. If your connecting the Hopkins 7-wire harness to this box, you'll probably have to ignore the wire colors names and just use the location (R Turn, etc.). Both are marked on each terminal. There are 5 different openings to choose from to route the wiring to this box and it comes with both rubber grommets to run wiring through and rubber plugs for the openings not used. A downside is that only the side with 2 openings has wire hold downs on the inside. It would have been nice if at least the opening on the opposite end also had such a feature. It's fairly water tight and installed easily onto the frame, under the trailer. Because it's lightweight plastic, I'm not so sure how long it'd last in the direct sunlight if it was mounted on the tongue or other exterior location. 106238
I love these boxes. I've repaired numerous trailers my sons and I own, including cargos, flat beds and horse trailers. I really like the grommet locations, cable clamping and posts for wire connections. There is plenty of room inside to neatly route wires. 108409
Well made product with a great design. The only criticism I have of the product is the cheap flat head screws provided with it. They should be stainless and the smaller ones Phillips head. If the screws were of be it would have gotten a five star rating. 341553
Rewired my trailer and used this junction box to go from my main cable to all the individual lights and brakes. It worked great, the only thing I didn't like about it was that it only had two cable clamps on the inside 314692
Chris B - 11/11/2017Installed in about 30 minutes, made install a breeze and took the mess out of a rats nest of wiring spliced under the trailer. Comes with plenty of grommets and all hardware to put together. You need to supply the bolts or screws to mount this to your trailer. Each terminal is labeled for what connects to it taking the guess work out of matching wires up. 442709
Richard P - 10/14/2018I purchased this product after researching current trailer rewiring methods. I recently had my entire 18' trailer wired and upgraded. The trailer is 8 years old and I wanted to replace the original 4 way trailer harness which the trailer manufacture had surrounded in electrical tape which also needed an adapter. After some research, I opted for this 7 way pigtail (50-67-005) which is the connector I needed my trucks and this junction box. (all contacts were current) The junction box is sturdy and well made, we installed 7 way wire within the box with a snug fit. The trailer now has a clean professional appearance and most test functions can be performed from the junction box location. The junction box was installed behind the trailer tongue frame to minimize the weather elements. This product appears to seal well as the product description indicates. I am very satisfied with this product and Etrailer's customer service. 59585
Junction box was great had it installed and wires hooked up in a little over an hour. Service and shipment was better than expected. Will definitely use etrailer for more of my needs, very good company. The only thing that took a while was the molded seven connector wire colors don't all follow standards, but a test light and a few minutes and it was figured out. 209099
Good selection at competitive pricing. 857468
Product looks exactly like picture and functions well. I have used this type of box on all my trailers to clean up wiring. 849530
This thing is awesome and should be a must have for everyone who has a boat with electric breaks. Cleaned up my wiring 10X no more blinking lights traveling down the road. Extremely secure connection to trailer, just make sure you get self locking bolts. Also makes grounding to your trailer a none issue and keeps wiring secure and clean traveling down the road. Easy self install too! 848770
First Class products and Service!! What more can you ask for?? This will be my primary trailer parts supplier. 831306
Well made. High quality posts. Good grommets. Good overall experience 824190
Nice stopped my dim lights and ground p roblems 820317
simplifies truck to trailer connections. Much better than wire nuts that were there. Water resistant, too 806367
The service rep was terrific. She analyzed the alternatives and made helpful add-on recommendations without any pushy "up selling." etrailer comes through once again! 807223
I ordered several items to fix a trailer that had a previous shade tree mechanic fix. Items came quickly and were affordable. Website is very easy to navigate. I like to do things one time. Etrailer allows me to do just that with their expansive inventory. I have ordered several times and will continue to do so. This junction box gave the rewire a finished look. It is a great to be able to connect wires instead of butt connectors and tape. Also allows future addition of work lights, extra marker lights, etc. Adding an additional brake axle would be easy to wire. 796089
Do you have a question about this Accessories and Part?
Info for this part was:
At etrailer.com we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.
Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.
Error submitting comment. Please try again momentarily.