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Trailer Wiring Junction Box - 7 Terminals - Polypropylene

Trailer Wiring Junction Box - 7 Terminals - Polypropylene

Item # 3375601100
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Buyers Products Trailer Wiring - 3375601100
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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. 1-636-306-4830 to order Buyers Products accessories and parts part number 3375601100 or order online at Free expert support on all Buyers Products products. Great prices and Fastest Shipping for Trailer Wiring Junction Box - 7 Terminals - Polypropylene. Accessories and Parts reviews from real customers.
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  • Reviews (158)
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Buyers Products Accessories and Parts - 3375601100

  • Trailer Wiring
  • Junction Box
  • Buyers Products

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.

  • Electrical junction box consolidates your truck's wiring
  • Polypropylene construction
  • Number of terminals: 7
  • 1-Year warranty

5601100 Buyers Products Electrical Junction Box - 7 Terminals - Polypropylene

Video of Trailer Wiring Junction Box - 7 Terminals - Polypropylene

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for Buyers Products Trailer Wiring Junction Box Review

Shane: Hi, I'm Shane with 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 That's going to do it for our look at the trailer wiring junction box..

Customer Satisfaction Score:

Customer Reviews

Trailer Wiring Junction Box - 7 Terminals - Polypropylene - 3375601100

Average Customer Rating:  4.7 out of 5 stars   (158 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.


Does everything you could ask a 7 wire polypropylene wiring junction box to do.


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.


Ordered this with multiple things. Only thing I received was the small disconnect switch with the cable. Had to wait on another whole kit to ship.


Works great. holds my wires and keeps them covered.


Love the product. It has worked well for my cattle trailer.


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


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.


All the items I ordered were as shown and described on the etrailer Web site. They came the second day after placing the order. Prices were better than anything local. Great people to work with. I will be using them again.


Use on many of our trailers, Great prod uct


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!!

One year later and the box is still holding up strong! Great product!
BrianB - 06/17/2020


I needed a trailer wiring junction box because my existing one rusted out. I looked all over, including the place where I bought the trailer, but was unsuccessful. I stumbled onto the etrailer site by luck and was amazed they had what I was looking for. I took some photos of my unit and compared it to what they were offering and it appeared pretty identical so I went ahead with the purchase. This company is very responsive and easy to deal with. The shipping was quick, the price was very fair, and the staff is attentive and professional. I’m glad I discovered etrailer.


Helped make my trailer project look very professional.


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!

Great! Still water proof and working fine.
Jon H - 07/25/2021


Great website. Detailed information on products. Easy Ordering and fast shipping.


Used when replacing connector and breakaway switch on my enclosed trailer. Was easy to use and install.


Very slow to ship


Order shipped quick! Everything as expe cted


quality construction


Excellent company to work with. Very knowledgeable and always on time shipments.


Very good junction box for the money. I used it to wire in a 7 pin RV and 6 pin round to vehicle.


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.

A year later, all is well.
Chuck - 01/31/2021


It's well built a good design


well made, attention to details with grommet sizes.

Working perfectly, highly recommend
Rick - 05/23/2022

Show More Reviews

See what our Experts say about this Buyers Products Accessories and Parts

  • Dimensions of the Trailer Wiring Junction Box
    The Trailer Wiring Junction Box # 3375601100 has dimensions of 8-1/2" long, 3-5/8" wide and 2-1/2" tall. The distance between the mounting holes (center of hole to center of hole) is 7-13/16". I have included a video that shows these measurements starting at the 2:15 mark of the video.
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  • Comparing Trailer Wiring Junction Box 3375601100 and Trailer Wiring Junction Box 38656
    The Trailer Wiring Junction Box part # 3375601100 and Trailer Wiring Junction Box part # 38656 are both pretty standard 7-terminal junction boxes. The latter is slightly smaller so there will be more places to mount it so that is what I recommend but you really can't go wrong with either option.
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  • Creating 7-Way Trailer Connection Adaptor for 13-Way European Bike Rack Lighing
    We do not have any European 13 way adapters to make your bike rack lights compatible so you will need to rewire it. So you would need to create a custom adapter using a 7-way connector and probably a junction box to protect an external converter box that you will need to separate the stop light from the turn signal for your 13 way bike rack wiring. For this conversion, I recommend the Vehicle to Vehicle Tail Light Converter # 118158 along with the Wesbar Adapter - 7-Way RV to 4-Way or...
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  • Correct Replacement 7-Way Trailer Connector Pigtail for Travel Trailer
    The pin-out for a 7-way trailer connector is pretty consistent. Unless the connector was wired incorrectly, it should be wired as shown in the provided photo showing the correct pin-out. What CAN vary is the wire color codes, which are also shown in the photo. The # H20046 pigtail would work just fine for you, just be sure to follow the wire color code shown on the linked product page. I'd also recommend a junction box like part # 3375601100. A junction box provides a centralized place...
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  • Taillight Converter Needed To Separate Brake Lamp and Turn Signal Circuits
    The Curt # C56196 2 to 3 wire taillight converter is exactly what you'll need to split out the turn signal function from the brake lamp circuit. However, keep in mind that the # C56196 is NOT compatible with LED lamps, unfortunately we don't offer a taillight converter at this time that is compatible with LED lamps. You would wire the converter inline with the right and left turn and brake circuits. You will want to install the converter some place where it's protected from the elements....
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  • Hopkins 7 Way Molded Plug Wiring and Junction Box for a Boat Trailer Wiring Harness
    There's not a universal way that trailers are wired. I have attached a diagram showing the three typical ways and this should also help you to connect to the 7-way harness you purchased once you identify your wires. Yours is obviously different, thank you for including the picture. To identify the wires on the trailer you will need to apply 12V power from a car battery to see what function each wire activates. Ground the battery negative terminal to the trailer frame and then one by one...
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  • Junction Box Terminal Post Size for Part # 3375601100
    The ring terminals you want to use with the junction # 3375601100 are the # 44-5310A which have an inner diameter of 3/16 of an inch.
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  • Wiring Harness and Junction Box for a DIY Trailer
    We do have a great wiring harness for DIY trailers. It is the 7-Way Molded Trailer Wire Connector, 4' Long item # H20043. The Pre-wired 7-Way Trailer Connector measures four feet long including the connector. To secure and consolidate all of your wiring connects you will want to use the Trailer Wiring Junction Box - 7 Terminal item # 3375601100. The weatherproof, heavy-duty plastic protects wires and terminals from the elements.
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  • Battery Disconnect Switch for Use on Travel Trailer
    You can use the Marine Battery Switch # 277-000403 for your application but since this item is not rated for outdoor use I recommend using a junction box like # 3375601100 to provide a degree of protection from moisture. The switch housing (not including the knob) is about 1-1/4-inches deep so you'd want to use hardware that is about 2-inches long. If space is available in your battery box you might be able to mount the switch there. In this case a better choice might be the Epicord Battery...
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    Yes, both connectors you mentioned are 7-way trailer end connectors with the same functions, so they do have the same basic use. The biggest difference is that theHopkins 7-Way RV Style Connector with Molded Cable - Trailer End - 8' Long - RV Standard Item # H20046 and is meant to be used with a junction box like the Trailer Wiring Junction Box # 3375601100. The other connector you asked about, the Bargman 7-Pole Connector # 54-67-525, is 1' long and comes with butt connectors so it is...
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  • Wire Gauge of 7-Way & Junction Box
    While we have an alternative, the part number you asked about has been discontinued. But what you can use is the Trailer Wiring Junction Box # 3375601100 and Hopkins 7-Way RV Style Connector - 8' Long # H20046. This 7-way uses 14 gauge wires for the red, brown, green, and yellow; 12 gauge for the blue; and 10 gauge for the white and black wires.
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  • Replacement Trailer Side 7-Way Connector with Junction Box
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  • Can Trailer 4-Way be Wired to Activate Trailer Brakes
    A 4-way is not able to activate trailer brakes as it is for lighting only, so it doesn't have the ability to carry the signals to your brakes. So what you'll need for your trailer is a junction box and 7-way: - Junction Box - 7 Terminal # 3375601100 - 7-Way RV Style Connector - Trailer End 6 ' Long # HM20086 or 8' Long # H20046 You'll wire your brakes (as well as your lights) directly to the junction box, which the 7-way is hooked up to. What you will need is brake wire, which is available...
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  • Should Junction Box be Used For Adding 7-Way & Wiring to Trailer
    For adding wiring and a 7-way to your trailer, a junction box and 7-way connector is absolutely the way to go, because it is the easiest way to connect your wiring. The best option for that is the following: - Junction Box - 7 Terminal # 3375601100 - 7-Way RV Style Connector - Trailer End 6 ' Long # HM20086 or 8' Long # H20046 If you need added components for install such as a wire tool, zip ties, circuit tester, butt connectors and more, you may want to consider getting that in one...
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    I have a solution for you, but we aren't going to have any 7 way connections and junction boxes that are wired with the same color wires/pin locations as the traditional wiring setups you're looking for. I recommend using the 7 way connector # 54-77-003 and hard wiring your plug the way you want it setup. You can get wire by the foot (12 gauge) # 12-1-1 or (10 gauge) # 10-1-1 and a Trailer Wiring Junction Box # 3375601100 to finish off this project. This will allow you to use the proper...
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  • Can Junction Box be Submerged When Rewiring Boat Trailer
    You can re-do the wiring on your boat trailer with a junction box, but a junction box cannot be submerged as they aren't waterproof. So if you are able to place the junction box in a location that allows it not to be submerged, the best option is the Trailer Wiring Junction Box # 3375601100. This comes with ring terminals and if you need wire we offer it sold by the foot with 12 Gauge # 12-1-1, 14 Gauge # DW02413-1, 16 Gauge # DW02359-1. You may also need Wire Loom # 459075-1 and a connector...
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  • Parts Needed to Add Back Up Lights & 7-Way Connector on Boat Trailer
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Expert Research:
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Employee Cole B
Installed by:
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Employee Shane H
Installed by:
Shane H
Employee Chris R
Video Edited:
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Edited by:
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