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etrailer Trailer Wiring 7-Way Upgrade Kit w/ Junction Box and RV Style Connector

etrailer Trailer Wiring 7-Way Upgrade Kit w/ Junction Box and RV Style Connector

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This kit includes a junction box so you can quickly and easily connect the wires from the included trailer connector to your trailer's wiring. Lowest Prices for the best trailer wiring from etrailer. etrailer Trailer Wiring 7-Way Upgrade Kit w/ Junction Box and RV Style Connector part number e99011 can be ordered online at or call 1-833-496-1390 for expert service.
  • All Info
  • Reviews (133)
  • Q & A (0)
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  • Why etrailer?

etrailer Trailer Wiring

  • Trailer Connectors
  • Junction Box
  • Trailer End Connector
  • 7 Round - Blade
  • Plug and Lead
  • 0 - 5 Feet Long
  • etrailer

This kit includes a junction box so you can quickly and easily connect the wires from the included trailer connector to your trailer's wiring.


  • Kit allows you to upgrade from a 4-way, 5-way, or 6-way connector to a 7-way connector
  • Pre-wired, 7-way, blade-style, trailer-end connector lets you connect your trailer to your vehicle
    • Flexible cable allows for easy positioning
  • Weatherproof, heavy-duty plastic junction box protects wires and terminals from the elements
  • Wire functions:
    • Black: 12 volt power
    • Yellow: auxiliary or reverse signal
    • Red: left brake and turn signal
    • Green: running lights
    • Brown: right stop and turn signal
    • Blue: trailer brakes
  • Ring terminals included


  • Overall box dimensions: 8-1/8" long x 3-3/8" wide x 2-3/8" tall
    • Distance between mounting holes (on center): 7-3/8"
  • Lid dimensions: 6-5/8" long x 3" wide
  • Cord dimensions: 60" long x 5/8" diameter

e99011 etrailer Trailer Wiring Junction Box with Plug - 7-Way

Item # e99011

Customer Reviews

etrailer Trailer Wiring 7-Way Upgrade Kit w/ Junction Box and RV Style Connector - e99011

Average Customer Rating:  4.8 out of 5 stars   (133 Customer Reviews)

This kit includes a junction box so you can quickly and easily connect the wires from the included trailer connector to your trailer's wiring.


Wiring was the hardest part of adding brakes to my trailer. This connector kit made it easier and look neater. It came with plenty of eye splices and cable grommets. You can run wires out of several places on the box, and they give you enough grommets to replace the solid plugs for all of them. Weather tight. My only issue was difficulty inserting the plug into the truck receptacle. I had to file off some material from the edge and wipe a little lubricant on the plug to get it to slide in. Absolutely weather proof when it is in place.
Just a reminder that colors on the wires probably will not match colors on your trailer wiring. I used a meter to confirm continuity between the plug and the wires in the junction box. Triple checked as I connected them and had no problem with power to anything on the trailer.


Seems like a good way to rewire a trailer. Unfortunately this didn't include the 2 screws to secure the lid of the junction box. Not sure if 8t was just my package that was lacking or if they are all that way. Defeats the entire purpose of all the weather tight connections to the box. Without the correct size screws the plastic box will strip out easy rendering it useless.

I will have our customer service team reach out to you. The screws are included to secure the lid to the junction box.
-- Etrailer Expert Jenny N - 02/16/2022


So far both the wiring harness and junction box kit are working well. Comes with loop connectors and grommets and has a small layout describing the functions of each wire. Would be nice if a diagram was included to match the wires from the trailer to the box since none of the colored wires match up, luckily [online videos] can fix that. I would recommend purchasing, its a good deal and not difficult to install.


The molded plug & sealed junction box is a 5 star upgrade. My old open plug would rust & the lights not work after a short time.

No problems at all. The sealed plug and junction box solved my moisture and corrosion problem. Thanks for a great upgrade to my trailer.
Michael - 04/16/2022


This is great kit for updating plugs on trailers with brakes.
It is so convenient to be able to check power at this junction box.
I have installed these on several trailers and I like them a lot.
etrailer is the by far the best place to get them, great price, fast shipping, super customer service.


Arrived fast and packed well, plugged it in and everything tested out Ok. I will add my wiring tomorrow. I will buy this again if I get another trailer.


The next best thing since sliced bread in trailer wiring. After using this the first time I've put one on any trailer I've had to do wiring work on. I've also used one on my pickup as a junction box that has worked much better and easier to add to or change out components than most "factory" T connections. Don't have intermittent issues with loose pins on plugs like the "t" splitters tend to have. 10/10 will purchase again and have already recommended it multiple times to friends/family.


This originally worked well and was straightforward to install. I recall one of the colored posts not matching standard colors, but it wasn’t an issue. I had to shorten the 7 way lead.

The plastic got brittle in the winter cold and I accidentally broke it at some point. I ended up replacing it with something made of a different kind of plastic.

If I were to do it again, I probably wouldn’t put anything like this on another trailer. Probably better for a gooseneck or fifth wheel.


Product is exactly as described. The quality is exceptional, delivery of the product was in a timely manner. The customer service at etrailer is awesome!


Overall the parts are great, the only reason I give it a 4-star rating because I think they could have sent some smaller terminals, the one comin with the kit is over sized for the 10-14 gauge cables most people use.


Great product, the wires in the receptacle were wired wrong as well as the instructions were wrong. Brown is running lights, green is right turn and brake, yellow is left turn and brake. I adjusted the wires in the box and all was good.


This what I have been looking for. Makes a neat junction box hidden under trailer.




I was rewireing a 12’ box trailer and purchased all my wire ring needs thru etrailer :
They were very courteous and professional all parts and equipment were good quality and just as I
ordered it :)
I am very happy and satisfied:


Order was left on the ground outside my front door in a snowstorm on a Sunday. I'm not open on Sundays. Picked up the soaked box on Monday morning.


This is the 5th one I’ve bought for five different trailers they make for an easy professional looking installation


This is perfect for the upgrade to my 16 ft trailer lighting that will work on our new 2021 Ram


Great product, easy to install
I didnt
have instructions, but used the etrailer you tube videos. I could not have done it without the videos. Works perfect a year later!


Looks like a good product I have yet to install it tho I like how everything is color coded it will make it easy to install


Fast Shipping as always!

Can't wait
to install once the weather warms up.


All are great products


Very high quality, could use better packaging! The box was ripped open when delivered, due to a very flimsy box!


Well informative people. Quick deliveries and great customer service. Have used them several times. Great results. Always


Looks great. Didn’t install it yet but it should do what I need.


Good Quality and easy to install

Show More Reviews

See what our Experts say about this etrailer Trailer Wiring

  • How To Replace a 4-Way Taylor Trailer Connector With 7-Way
    The wires on your 4-way trailer connector are as follows: White - Ground Yellow/Brown - Left Side Trailer Running Light Green/Brown - Right Side Trailer Running Light Yellow - Left Side Trailer Stop/Turn Light Green - Left Side Trailer Stop.Turn Light Red - Misc. In order to rewire the above to a standard 7-way trailer connector you just need to match the wires based on function but the yellow/brown and green/brown wires can just be joined as one and then attached to a running light wire...
    view full answer...
  • Wiring Diagram for Installing etrailer Junction Box Upgrade to Utility Wiring Colors
    The only version of the etrailer wiring 7-way upgrade kit part # e99011 that we offer is this one that has the RV wiring colors. The best solution I can provide to help with that is a wiring diagram that has both color setups for you to compare and use when installing this.
    view full answer...
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  • Recommended Trailer Plug for Starcraft Truck Bed Camper
    In order to attach a Starcraft Truck Bed Camper to a standard trailer connector you will need to remove the existing trailer connector and replace it as I am not aware of any adapter to use a standard trailer connector. For this, I recommend the etrailer Trailer Wiring 7-Way Upgrade Kit part # e99011 which gives you exactly what you need to attach to a standard 7-way trailer connector.
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  • Why Do 4 to 7-Way Trailer Connector Adapters Have Missing Pins Inside the 7-Way Plug
    In order to convert a trailer from a 4 or 5-way flat to a 7-way round you will need to use the etrailer Trailer Wiring 7-Way Upgrade Kit w/ Junction Box part # e99011. The reason for this is because 4-way or 5-way flat trailer connector only carry circuits for stop/turn, running, and sometimes reverse lights. The 7-way has all of these circuits as well a brake output and a battery charge line.
    view full answer...
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  • Easiest Way to Rewire 7-Way Wiring of 2004 American Pace Utility Trailer
    The best option for rewiring a trailer is the 7-way junction box kit part # e99011. You'll mount the box on the frame rail (or wherever works best) and then run the wires for all of the individual circuits to it and you'd be set.
    view full answer...
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  • Easier Way to Wire in a 7-Way to a Trailer that Has 6-Way
    The easiest way to upgrade a trailer to a 7-way or wire in a new 7-way would be with the 7-Way upgrade kit part # e99011. The junction box mounts on the trailer and then all of the wiring then runs to the box and you're set. You wouldn't want or need to also run a 4-way harness to it as well. If a trailer needs the 7 circuits to function there wouldn't be a way to tow it with just a 4-way.
    view full answer...
  • Can 7-Way Upgrade Kit w/ Junction Box e99011 be Used on Utility Trailer
    Yes the etrailer Trailer Wiring 7-Way Upgrade Kit w/ Junction Box and RV Style Connector # e99011 will work great on a utility trailer. The 7-way blade connector it has is typically referred to as an RV style connector but it's more and more getting used on utility trailers. There's no reason at all it couldn't be used on a utility trailer. Most trucks have the 7-way connector that this matches to. Some say there's a utility and RV style 7-way but in reality the only difference is the color...
    view full answer...
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  • Recommended 7-Way Connector For Cargo Trailer With Trailer Brakes
    The factory 7-way connector on your 2012 Porsche Cayenne Base is the 7-way RV Standard. For a compatible trailer side 7-way connector for your cargo trailer I recommend the etrailer Trailer Wiring 7-Way Upgrade Kit w/ Junction Box and RV Style Connector # e99011 which includes the required 7-way RV standard connector, and gives you a junction box to make all of your wiring connections. I included a video of the # e99011 being installed for you to take a look at.
    view full answer...
  • Can You Change 6-way Connector to 7-way To Power 12v Fan In Trailer
    It sounds like you have a solid plan! To power your 12v fan I recommend replacing your 6-way connector with the etrailer Trailer Wiring 7-Way Upgrade Kit w/ Junction Box and RV Style Connector # e99011 which gives you a nice junction box to make all of your wiring connections, and will allow you to run power wires from the 12v pin of the 7-way connector to your 12v fan and accessory lights. Keep in mind that this circuit is not made to power too many things at once, so if you have quite...
    view full answer...
  • What Size are the Wire Studs in the Junction Box Included with Trailer Wiring 7-Way Upgrade Kit
    I went out to the warehouse to measure the studs on the junction box that comes with Trailer Wiring 7-Way Upgrade Kit # e99011. The studs are 3/16 inch. The kit does also include the appropriate size nuts as well as 3/16 and 1/4 ring terminals. I have linked a video showing an example installation for you.
    view full answer...
  • How To Wire a 7-Way Trailer Plug To A Vehicle With 6 Wires
    I am not sure which side you are referring to, the vehicle or trailer but regardless you will need to test the wires for function instead of color matching. In order to do this on the trailer side you will need to apply 12 volt power to each wire and see which light it illuminates. In order to do this for the vehicle side you will need test each wire with a circuit tester while applying the respective signals in the tow vehicle. If you are installing a trailer side 7-way trailer connector...
    view full answer...
  • Kit to Upgrade 5-Way on Trailer to 7-Way
    We have a kit that's designed for exactly what you are looking to do. The Trailer Wiring 7-Way Upgrade Kit part # e99011 is designed for upgrading a trailer from a 4-way to a 7-way but can also be used with 5-way wiring as well very easily. I attached an install video for this kit for you to check out as well.
    view full answer...
  • Trailers Right Blinker Light Causes Both Lights to Blink
    Checking the grounds first was the right thing to do since what you're experiencing is generally a ground issue. Since you've already done that you might replace the mounting hardwarwe for that light to see if the issue is still a ground. Also, do the same work on the main trailer ground if you haven't already. Have you towed a different trailer with the same truck or tested the connector at the truck? If not you should just to make sure the problem is on the trailer side. Make sure...
    view full answer...
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  • 7-Way and Junction Box Kit Recommendation for Trailer with 4-Way
    I'd go with adding a junction box and a 7-way but still using your current light's wiring if it's still good. For that we have the part # e99011 which matches what you need perfectly. It's designed for upgrading a trailer with a 4-way to a 7-way and comes with a junction box and 7-way. I attached an install video for this for you to check out as well.
    view full answer...
  • Does Trailer Wiring 7-Way Upgrade Kit # e99011 Come with Ring Terminals
    Actually the Trailer Wiring 7-Way Upgrade Kit # e99011 that you referenced comes with the needed ring terminals so you would not need to provide any. The two sizes though are 3/8 and 3/16.
    view full answer...
  • Parts Needed to Add 7-Way to Trailer to Power Trailer Interior Lights
    You'll have to convert the trailer to a 7-way so that it will have the 12 volt accessory circuit which will allow you to power the interior lights. The part # e99011 is designed for exactly what you are looking to do so it would be the best option for adding the 7-way. You'll want to run a length of wire from the junction box for the 12 volt circuit to the interior lighting as needed.
    view full answer...
  • Upgrading 4-Way of Trailer to 7-Way to Wire Battery for Powering Trailer Interior/Exterior Lights
    For what you are looking for the standard solution that is tried and true is to install a vehicle battery in the trailer to power the lighting of your trailer. What you'll want to do for the trailer wiring is install the junction box 7-way kit # e99011 this is specifically designed for upgrading a trailer like yours from a 4-way to a 7-way. If you check out the picture I attached you'll see what the junction box does basically. The ring terminals on the bottom side of the posts are from...
    view full answer...
    Image 1 for
  • Which Axle if only one Should Have Trailer Brakes on Tandem Axle Trailer
    We recommend putting the brakes on the axle that will have more of the cargo's weight on it. For a utility trailer that's typically the front axle. Typically the only time you see the brake axle as the rear axle is if it's a boat trailer since the weight of the engine is behind the axles.
    view full answer...
  • Wire Function to Replace a Trailers 6-Way Connector with a 7-Way
    Are you trying to replace a 6-way on a trailer with a 7-way connector, like part # e99011? Traditionally, the white, brown, green, and yellow wires are as you listed them. Then the other 2 wires are for electric brakes and a 12 volt auxillary circuit. However, wire coloring is not always standard and can be very unreliable. Instead I recommend testing each circuit for function. Use a 12 volt battery and connect the negative pole to a good ground and then connect each wire, one at a...
    view full answer...
  • Replacing a Trailers 6-Way Connector with a 7-Way Connector
    The easist, and most sure way to know which wire is which function is to provide power to them, one by one, and see what happens. Wiring by function is unreliable because even though there is a traditional wire color code it isn't standardized by any means. Once you have found the functions of each wire you wan the pins on the new 7-way to be in the following pattern: 1 O'clock - Tail and running lights 3 O'clock - Left turn and right brake lights 5 O'clock - Ground 7 O'clock - Brake...
    view full answer...
    Image 1 for
  • Kit Needed to Convert 4-Way of Trailer to 7-Way
    We have a kit that is designed specifically for converting the 4-way of a trailer to a 7-way. For that you would want the 7-Way Upgrade kit part # e99011 which comes with everything needed. I attached an install video for this kit for you to check out below as well.
    view full answer...
  • Replacing a 7-Blade to 6-Square Trailer Adapter on a Pop Up Trailer
    What you have is an adapter that goes from a 7-way blade connector to a 6-way square connector. A few pop up trailer manufacturers used it but unfortunately replacements can be hard to find. In my opinion you would be better off cutting the 6-way off of the trailer and just hardwiring in a 7-way connector and not deal with the adatper. The easiest and cleanest way to wire in the new 7-way is with a junction box. We have part # e99011 that includes everything you need. I've also linked...
    view full answer...
    Image 1 for
  • How To Replace a 4-Way Trailer Connector with a 7-Way Trailer Connector
    The best option we have for you to upgrade the 4-way trailer connector on your trailer to a 7-way trailer connector is with the Trailer Wiring 7-Way Upgrade Kit part # e99011. Once you have this all you need to do is run the wires from the trailer lights to the junction box and then from the junction box to the trailer connector. Inside the junction box, the terminals are labeled by both wire color and function. However, when running the wires from this trailer connector to the junction...
    view full answer...
  • Wiring Kit to Convert Trailer Wiring to 7-Way Format
    Trailer Wiring 7-Way Upgrade Kit # e99011 allows a trailer's existing 4-pole, 5-pole or 6-pole wiring to be re-formatted to the 7-way RV standard to match the 7-way socket on your Silverado. The kit includes a male trailer plug and cable, hardware and ring terminals to allow you to wire both the male plug/cable's leads and the existing trailer wires together inside the included junction box. The kit also includes protective wire loom to keep any exposed trailer wiring protected from road...
    view full answer...
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Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Jameson C
Expert Research:
Jameson C
Employee Joshua S
Video Edited:
Joshua S
Employee Jacob T
Video Edited:
Jacob T
Employee Kathleen M
Installed by:
Kathleen M
Employee Bradley B
Installed by:
Bradley B
Employee Dustin K
Video by:
Dustin K
Employee Jonathan Y
Video by:
Jonathan Y
Employee Wilson B
Updated by:
Wilson B
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Updated by:
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Updated by:
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Employee Kristina F
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