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  1. Trailer Wiring
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  4. Single-Function Adapter
  5. 7 Round - Blade
  6. Plug and Lead
Adapter 4 Pole to 7 Pole Vehicle End Trailer Connector

Adapter 4 Pole to 7 Pole Vehicle End Trailer Connector

Item # 30717
Our Price: $31.63
Trailer Wiring
Shipping Weight: 0.57 lbs
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30717 - 4 Flat Tow Ready Wiring Adapters
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Great Prices for the best trailer wiring from Tow Ready. Adapter 4 Pole to 7 Pole Vehicle End Trailer Connector part number 30717 can be ordered online at or call 1-800-940-8924 for expert service.
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  • Reviews (589)
  • Q & A (0)
  • Videos (5)
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Tow Ready Trailer Wiring - 30717

  • Wiring Adapters
  • Single-Function Adapter
  • 7 Round - Blade
  • Plug and Lead
  • 0 - 5 Feet Long
  • 4 Flat
  • Tow Ready

  • Adapter converts from 4 pole wiring on vehicle to 7 pole round plug
  • Additional wire leads for brake, power and accessory are 12" long
  • Mounting bracket (18138) is sold separately

Wiring diagram

Product detail

20321 Adapter 4 Pole to 7 Pole Vehicle End Trailer Connector

California residents: click here

Video of Adapter 4 Pole to 7 Pole Vehicle End Trailer Connector

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 - 30717 Review

Customer Satisfaction Score:

Customer Reviews

Adapter 4 Pole to 7 Pole Vehicle End Trailer Connector - 30717

Average Customer Rating:  4.8 out of 5 stars   (589 Customer Reviews)


This product works as expected. There is not too much to the installation, just plug it in properly and mount the ground wire.
I did not find an easy way to mount this to my wife's Odyssey, or to the trailer hitch (item# 75270). Luckily, I do prototype design and manufacturing. So I came up with my own solution. I designed and made my own bracket to mount the 7 pole to the trailer hitch. It works like a charm, and looks great!


i had to replace these two items as my dear daughter went down our goat path driveway too fast. they replaced the originals from etrailer from the prior year. shipping is timely and customer service actually helps! i wired from battery to controller to hitch myself, and everything fit.



its working well, no issues.


Joe at etrailer was able to provide this solution and saved me literally hundreds of dollars to have a reputable place put in a new harness onto my AWD MKX. Thank you!



The adapter worked out perfectly. And now after almost a year no issues whatsoever.


The staff is very friendly. I would have awarded 5 stars but there was a shipping issue. They did get me all the parts I ordered, with simple communication, a couple pictures and minimal frustrations I got everything over two shipments. It took a little longer to get everything then anticipated. They deserve 4.5 stars not just a 4. I will do business with them again and I do recommend them. Will be ordering a receiver hitch through them this spring.


I was really skeptical about this adapter but for no reason! Installed in about 10 minutes using etrailer mounting bracket, dielectric grease, a couple zip ties, and some electric tape. Worked perfectly the first time I tested it on my trailer.


this connector along with the short L bracket and the mount bracket- gave me a nice connector to my hitch.
Though I used the short connector and did have to slightly bend it to allow the 4 to 7 pole connector to fit.

If Id bought the long L bracket-- It could have worked-- but bending a little worked well.


Works great. Easy install.

more sensitive to dirt than I expected, but that might be common to all trailer connections, I don't know. I noticed on a trip that my brake controller said NC (no connection), and I didn't have trailer brakes, which meant my blinkers probably hadn't been working, either. I got pretty worried, and looked at it and only saw just a little black gunk on one blade. But cleaning that small amount of black gunk off solved the problem.

So far, so good!

Etrailer Expert

Laura E.


Thanks for your business and your review, Zach! Using dielectric grease like 11755 on your connections increases reliability and the life of the connection by preventing corrosion and sealing the connection.


Works great! Remember to ground it to: 1) tow vehicle frame, or 2) directly to tow vehicle negative terminal. Do not ground it trailer frame because you need to complete the circuit to the tow vehicle battery.


Wiring harnesses will simplify the job I'm doing glad that I found these products and I also had a good experience dealing with etrailer they keep you informed about shipping and the products are ship fast. Thank you


This 7 point harness wired right in with my T1 connector and is great for hooking up to my camper, very easy to install!


Every time etrailer has provided me with the needed wiring!


There was no splicing wires, it was plug-and-play, highly recommended, very easy installation


I wanted to show the custom installation. I did not want it under the bumper


Super Service at ETrailer - I have never had an issue with the help provided or with any product



Was easy to install. Fit perfect. Has stayed looking great. It is great having a mounting bracket for the electrical hookups. It keeps the 7pin more out of the way and more solid.


I really appreciate you following up on my order. The information and videos will help when I drop the harness and circuit breaker off at my local shop. When I went to them originally with my problem I couldn't answer all their questions. With the parts in hand they should be able to convert my four prong to the seven prong plug used on my new trailer. Thanks also to Craig at CampInn for directing me to your site and the parts they are using in the construction of my trailer.


Works great to get the 7 pole connection that I needed for my trailer.


Every phone encounter I’ve had with etrailer has been excellent. Their staff on the phones know their stuff and they have most every rv/trailer accessory known to man. The seven pole side is much more robust than the four pole side, which I leave connected all of the time. Problem solved


I bought this because I hated the flat four pole that just hung over the bumper. Drilled a 1 7/8 inch hole in my bumper with bimetal hole saw. Mounted nice and clean. Be sure to hook up the White ground wire to your frame. The ground wire from the flat four does not pass thru this connector. Also if need be you can still pull a trailer with a flat four pole just by unpluging it

Carl M.


It’s a year later. Still working great no problems


Has been working great since purchased and installed 3 months ago. Used for several different trailers and long distance trips. Easy to install. Had to be slightly creative with the attachment of the ground. Did not see a reason to have a ground on this portion since everything else is already grounded, however would not work without grounding to the frame. Only used the four way connection and taped remaining three back. Hope for good things to come with this produce. Highly recommend this product.

Mike G.


Had the same issue with the ground kurt. Almost gave up on it until I read your post. Thanks.



Thank you so much. Ours wasnt working either until we grounded it to car frame.


This is a great product . The price was $18.00 dollars cheaper than some I found online. I have a 2002 dodge ram 1500 pickup, this adapter will change the 4 pole( which is made on my truck) to a 7 pole( which is on the trailer I will be using). The product connected, and bolted up to my truck bumper very easy. E trailer is the best.



Im still enjoying this product, Ive used it several times, still workingwell


Hitch was as advertised. The printed instructions made it a breeze. Took about an hour with me and an experienced mechanic. The light kit took a little longer than expected but was installed inside the car vice behind the lights like the video showed. Towing a camper this weekend, not expecting any issues.

B K.


All is well. Don’t use it that often but when I needed it they’ve been there. I’ll use etrailer from now on.


The website was extremely easy to use especially with the feature to pick my vehicles connection and my trailers connection. My purchase arrived very promptly and the customer service was excellent. The adapter works perfectly and I will definitely shop from etrailer again.

Ben B.


I appreciate the follow-up. I must say that your company has provided an excellent customer service experience for me. I wish more companies cared as much. The product still works great. I use it when towing my trailer regularly.


Used this adaptor to replace the factory tow package flat 4-pin connector on my 2019 Toyota Highlander. It's sad that Toyota is still using a cheap flat 4-pin connector on their factory tow package for a vehicle rated to tow 5,000 LBS. Would it really have cost that much extra for them to just use a round 6- or 7-pin connector to begin with? The installation was pretty straightforward using a new mounting bracket for the round 7-pin connector in place of the existing 4-pin bracket. I hooked up the white ground wire to the mounting screw for the new bracket after sanding paint off the bracket and nut and using dielectric grease for the ground wire and 4-pin connections. Spent some time re-routing and zip-tying wires and taped up the 3 wires on the adaptor that I won't be using. Nice clean installation. Trailer running lights, turn signals and brake lights work great. A quality product delivered in a timely manner by


We only discovered this site recently and LOVE it. You don't have to know what you want, the questions lead you to exactly what you are needing. The item is of great quality, and as described. We can now swap from truck to jeep with our trailer, and simply without effort.

We have found our new 'to go' store for our trailer shopping. Customer Service by the way, terrific, great communication, and very quick shipping. Really Great Experience, Highly recommend.



Weve moved in the past year, our new home 250 miles away from our old one. We used the hitch a lot, did I say a lot? daily round trips, never had a single problem with it. Worked like a champ. Thanks


Average quality part, would be nice to include a mount but ended up going the extra mile and used a hole saw to install it in my van’s bumper out of harms way. Would be easily damaged if mounted near the hitch.

Etrailer Expert

Sierra K.


Item # 18138 is the mounting bracket that works with this wiring.

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