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7-Way Round Pin to 4-Flat Adapter

7-Way Round Pin to 4-Flat Adapter

Item # 118709
Our Price: $13.71
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Trailer Wiring
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Shipping Weight: 0.33 lbs
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118709 - 7 Round - Round Tow Ready Wiring Adapters
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Tow Ready Trailer Wiring - 118709

  • Wiring Adapters
  • Single-Function Adapter
  • 4 Flat
  • Plug Only
  • 7 Round - Round
  • Tow Ready


  • Adapts a 7-way round pin to 4-flat connector

118709 Tow Ready 7-pin to 4-flat Adapter

Video of 7-Way Round Pin to 4-Flat Adapter

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

Video Transcript for Tow Ready Wiring - Wiring Adapters - 118709 Review

Today we're going to be taking a look at part number 118709. This is the Tow Ready 7-pole round pin to 4-pole flat wiring adapter. It's a nice compact design. It's going to promote quick and easy conversion of your 7-pole connector to your 4-pole flat connector. It's going to allow one vehicle to tow either campers or boat trailers without electrical brakes. Now it looks like this is going to allow us to connect your ground, left turn, right turn and stop circuits. Tow Ready makes this from a noncorrosive construction that's with the outer and inner components.

It's got the nice easy grip design as well that's going to allow for a quicker connection and disconnecting. We'll go ahead and take a measurement of the overall length just to see how compact it is. It looks like from edge-to-edge it's going to give us a measurement of about 4-1/4 of an inch. It is designed for vehicles with 7-pole round pin connectors. You can see here that the 7-pole round pin portion only has the necessary contacts installed for the 4-pole flat connector. A very simple operation and connection.

All you have to do is plug the 7-pole into place and then here on the back side of the plug you're going to be able to make the 4-way flat connection. That's going to do it for our review of part number 118709. This is the Tow Ready 7-pole round pin to 4-pole flat wiring adapter. .

Customer Satisfaction Score:

Customer Reviews

7-Way Round Pin to 4-Flat Adapter - 118709

Average Customer Rating:  4.9 out of 5 stars   (63 Customer Reviews)


Fantastic customer support. There was a mix-up with the parts I ordered that was remedied quickly. Thanks Carol!


Works great. There are lots of trailers that aren't self-braking and four-pin addresses them perfectly. But what do you do when the prime mover is equipped with the newer 7-round connector? Why, you buy one of these adapters and your problem is solved.
Heavy duty, extremely well made, and a great price! is great.


I used this product along with your Trailer End Connector - 4-Flat - Coiled cord - item #54000-026, on the lights on our Brent and Parker grain wagons. This has worked out great so far. We haven't had the problem of too much or too little cord for the trailer lights, which allows the cord to get pinched and cut or stretched and broke. I just need to come up with a method of securing the cord and plug to the trailer tongue when not in use.


I am very satisfied with how quick I received the item. I ordered it the afternoon of October 13th, and received it the very next day after I placed a 2day shipping to get it on Monday October 17th. 100% satisfied!!! I will be ordering from you guys again


Works fine. It's a pin adapter that makes lights work. No issues


They work perfectly for the application they were intended for.


Quality of 7 way adapter


Work great


Replaced broken 4 flat to 7 round adapter from refit 2-3 years ago on Brent grain trailers. Refit is a big improvement over factory wiring at the hitch. Replaced the straight wire with coiled cable from hitch to tractor.


This adapter fits a 7 way round pin power cord SAE j560 connector (like on a semi tractor) to a flat 4 plug for a light duty trailer.

It is exactly what is described, and was shipped ASAP. Great job.


Looks solid. Prompt service and delivery. Note that this adapter is fully molded.

Stanislav - 12/14/2020


My GLE350 has a 7 pin plug but my Kendon m/c trailer has a 4 prong flat plug. This is an excellent solution! Heavy duty, extremely well made, and a great price!


I cant really review the products I have purchased, which consisted of various adapters for towing trailers, however I can tell you this place/site is amazing, they offer a wide array of products from A to Z, all under one roof, perfect for one stop shopping...their prices are very competitive and the service is outstanding!


Works great!


ETRAILER was the only I could find the electical adapter for my truck to my trailer. they delivered. The adapter worked as expected.


It's not about the product here, what's the difference between one adapter and the next? Not much, it's about the service and support from the AWESOME team here at etrailer. They make sure to let you know all the details of each product and even double checked that something I ordered would work for what I want....and it didn't so saved me time and trouble of returning it. Though that process is also great with them too. Thanks again for a great experience ETrailer!! Look forward to the next time.


Product was just as it was advertised and the service was better than expected! Super fast shipping and vendor stayed in email contact from the time the item was ordered until it was received.
I plan on using etrailer for future orders for my truck needs.


Very handy adapter for the 7 pin round socket to flat 4 pin


Quality products at a fair price

Thank You, and it is working wonderfully.
Bill C - 11/02/2017


Product is very durable. I ordered this product with a 3 day delivery. It showed up in exactly 3 days. Very happy with etrailer.


Searched far and wide for this particular adapter for my Silverado. This was the only place I could find it. Works like a champ. Order was processed and shipped quickly. Highly recommend.


Thanks, was exactly what I needed, can’t wait to try it out!


Product works well, owned for a year now still works well after plugging in and out! Several times! I’d buy agin if somehow I lost it!
Thank you


It worked as expected and seems to be of good quality.


This product was exactly what I needed and has worked very well for me. Highly recommend.

Show More Reviews

See what our Experts say about this Tow Ready Trailer Wiring

  • Adding Fog and Reverse Lights to ISI-1185 Socket
    You may be able to add either the fog lamps or the reverse lights -- but not both -- using the center pin on your current socket. That is, as long as the center pin isn't being used on both the trailer and the truck. To add the other function you will need a separate connection since all other pins are being used.
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  • Recommended Adapter to Connect 7-Way Round Pin to 4-Flat Connector
    The Tow Ready 7-Way Round Pin to 4-Flat Adapter # 118709 referenced in your question is designed to adapt a 7-way round pin to a 4-flat connector that you can hookup to a trailer that has a 4-way. If this is what your trailer uses, and your existing 7-Way round has the traditional pins as depicted below, then this will work great. I am not positive how you were connecting the harnesses before, so I can't be sure as to why the brake lights were not working. This adapter will provide an...
    view full answer...
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  • Can a European 7-Way Trailer Connector be Converted to a U.S. 4-Way
    No. The 7-Way end in the # 118709 adapter is made for the North American style of 7-Way round pins. A European 7-Way, see picture, has separate turn signals and brake lights and a circuit for fog lamps. The tail lights are also separate. You would need to fabricate a special adapter to get the 2 to work together. I would need to know which end has the European 7-Way, the vehicle or the trailer. It would also require a semi-permanent change to the connector on the vehicle or possibly the...
    view full answer...
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  • What to Do with 12 Volt Circuit when Adapting US 7-Way Trailer Connector to European 7-Way
    If the European 7-Way trailer connector does not have a 12 volt circuit (which it shouldn't) then you will not have to do anything with that circuit on the vehicle side. When you add a US style 7-Way to the bike rack that circuit will just dead end at the connector. If there is a loose 12 volt circuit wire then you can just use a wire nut or electrical tape and just cap it off and stow it out of the way.
    view full answer...
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  • Will the Tow Ready 7 Round Pin Adapter Allow My Freightliner Pull My Utility Trailer With a 4-Way
    If the plug on your Freightliner is a traditional vehicle side 7-way round pin connector like the one in the picture provided, and it is pinned the same then the Tow Ready 7 way to 4-Flay adapter part # 118709 would work out great. If you use this connector then no additional diodes would be needed.
    view full answer...
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  • Splicing in a 7-Way Trailer Connector to Trailer Tail Light Kit # TL5RK
    The issue is that on the 7-Way you bought the wire colors and functions do not match the 4-Way in the light kit. On the 7-Way it has the following wire colors and functions: White is ground Red is left turn/brake lights and will connect to the yellow wire on the light kit Brown is right turn and brake and will connect to the green wire on the light kit Green is tail lights and will connect to the brown wire on the light kit Blue is for trailer brakes Black is for 12 volt power Yellow is...
    view full answer...
  • 7-Way Round to 4-Way Flat Adapter Recommendation
    As long as the 7-way round you have on your trailer is wired so that the stop/turn circuits are on the same circuits the # 118709 would be perfect for what you are trying to do. If the 7-way you have is a Euro style that has separate taillight circuits then you would need to make an adapter, but I doubt this is this case. If your 7-way is wired like the diagram I attached you would be good to go.
    view full answer...
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  • Availability of 7-Way Round to 4-Way Trailer Wiring Connector
    Since you have a 7-way round connector the correct adapter is the part # 118709 to go from that to a 4-way.
    view full answer...
  • European 7-Pin to US 4-Way Flat Trailer Wiring Adapter for a Land Rover Defender
    There is a specific adapter for Land Rovers that have that European 7-Way connector # 118710. One end plugs into the vehicle 7-Way and the other end has a connector for a 4-Way flat connector used on US trailers.
    view full answer...
  • Adapter Recommendation to Go From 7-Way Round to 4-Way Flat
    You have a 7-way round connector on your truck so you would instead need the part # 118709 and not the # 47345 that you referenced.
    view full answer...
  • Solution for Trailer Brake Controller that Activates with Vehicle Hazard Lights
    What you need is the part # 5501. This adapter is designed for your exact application. It will allow your hazards to illuminate and function without activating your brake controller each time the lights come on. I attached a diagram that details how it installs as well.
    view full answer...
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  • Using Separate Brake Lights and Turn Signals on a European Trailer with US Chevy Silverado
    The issue is that trailers in the US use a combined lighting system where the brake lights and turn signals are on the same circuit. European trailers have a separate circuit for each function. The wiring harnesses for US spec vehicles will take the separate brake light and turn signals and combine them for use with a US trailer. If you plug in a European trailer then it would function like a US trailer. To fix this issue you can install a converter on the European trailer. Converter #...
    view full answer...
  • Is a European 13-Way to US 4-Way Adapter Available
    Unfortunately we do not have an adapter to go from a European 13-way trailer connector to a U.S. style 4-way trailer connector. European trailers typically have separate brake light and turn signal circuits, but U.S. trailers use a combined wiring system that use one wire for the turn signals and brake lights. You could make an adapter using a universal 4-way flat tail light converter like part # 119130, but you would need to find a European trailer side 13-way connector that can be rewired....
    view full answer...
  • Changing a US Style 7-Way Vehicle Connector to a European Style 7-Way Connector
    The European 7-Way does the same thing that the US 4-Way does. There isn't an adapter available because the European 7-Way has separate circuits for nearly every function on each side of the trailer. The US style 4 or 7-Way has combined brake lights and turn signals. What you will have to do is change over the US style 7-Way to a European one. You will need 1 European style vehicle side 7-Way and one special converter that separates the combined signals to separate ones. You will need...
    view full answer...
  • Wiring US 4-Way Trailer Connector to Trailer with European 7-Way Trailer Wiring
    Since you want to go from a 4-way on your vehicle to a trailer with a European 7 flat, you will simply be able to use the Tow Ready Vehicle to Vehicle Tail Light Converter # 118158 (this doesn't work with LED lights). This will take the combined stop and turn signal wires on your 4-way and separate them for your European 7-way. You will connect the 4-way color-for-color and the running light will run around this adapter versus through it, and the ground will need to be spliced so it can...
    view full answer...
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  • Trailer Wiring Harness Recommendation for a 2014 Volkswagen Golf TDI
    The wiring harness you would need for your 2014 Volkswagen Golf TDI would be the Tow Ready wiring harness part # 119190KIT. This is a universal install harness that will require you to tap into the turn signal wiring to install and will require you to run a wire up to the vehicle battery. I attached an install video and a help article that details how to find the best way to route the power wire up to the battery. To access the taillight wiring you will need to remove the interior panels...
    view full answer...
  • Diode Wiring Kit Recommendation for 2014 Ford F-150 Towed by Motorhome
    I recommend Roadmaster Universal Hy-Power Diode Wiring Kit part # RM-154. This kit is a confirmed fit for your 2014 Ford F-150. It wires diodes into your existing F-150 wiring and will use the factory lights when towing. We have detailed instructions for you to review, see link, and a video installation of this kit also.
    view full answer...
  • Recommended Adapter To connect 4-way Flat Trailer Connector To 7-way Round Connector On 2002 Volvo
    If you have a 7-way round pin connector on your Volvo, the adapter you can use is part # 118709. If the vehicle connector is round but has blade connectors and you want to attach a 4-way flat connector on the trailer you need part # PK12716.
    view full answer...
  • Can Hopkins Smart Hitch Camera be Used With 4-Way?
    You would not be able to use the 7-Way Round Pin to 4-Flat Adapter # 118709 to install the Hopkins Smart Hitch Backup Camera and Hitch Aligner System # HM50002. This camera and aligner requires a vehicle to have either a factory tow package or to be hardwired into the vehicle. I've added a link to the installation instructions for you to take a look at as well as a link to a video review of this system.
    view full answer...
  • Wiring US 4-Pole Trailer Connector 2014 Ford F150 to For Trailer with European 7-way
    I am not aware of the existence of an adapter, but one could be easily constructed. You will need to find a vehicle-side socket to receive the plug from your trailer. We do not carry them, so you will need to obtain one locally. You will also need a vehicle to vehicle taillight converter like part # 118158 and a trailer side 4-pole like part # 18004. You would then wire the converter as shown in the diagram I provided. Using this adapter will separate the turn signal back out so that...
    view full answer...
    Image 1 for
  • 7-Way to 4-Way Adapter for a 1998 Ford F-150
    What you have there on your 1998 Ford F-150 is a 7-Way blade style connector, not a round pin connector. So for an adapter to use trailers that have 4-Way flat connectors I recommend # PK12716. I have linked a video review of this adapter for you.
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    Image 1 for
  • Can a 12 Volt Battery on a Dump Trailer be Charged from a 7-Way Trailer Connector
    The 12 volt circuit on most 7-Way trailer connectors is fused at 30 amps/12 volts. At best it can provide a maintenance charge to a trailer mounted battery. But it cannot charge up a battery; at least not one that is the size of the battery used to operate functions on a dump trailer. Most vehicle alternators are not strong enough and the tow package wiring not large enough for enough amperage to get back to the battery. I recommend using an AC charger when you can to charge and recondition...
    view full answer...
    Image 1 for
  • 7-Way to 4-Way Adapter Recommendations
    If you have a blade style 7-way you would need the part # PK12716 to convert it to a 4-way. If instead you have the less common 7-way round you would want the part # 118709.
    view full answer...
  • Adapter for 2015 Audi Q5 to go From 7-Way to 4-Way
    The 7-way you have on your trailer is most likely a 7-way blade style connector so you would need the part # 47345. If you happened to have a 7-way round pin connector instead the adapter you would need is the part # 118709. The adapter you referenced is designed for Euro style connectors which wouldn't be what you have.
    view full answer...

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