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Adapter 4 Pole to 7 Pole Vehicle End Trailer Connector

Adapter 4 Pole to 7 Pole Vehicle End Trailer Connector

Item # 30717
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Our Price: $33.88
Trailer Wiring
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Shipping Weight: 0.57 lbs
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30717 - 4 Flat Tow Ready Wiring Adapters
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Lowest 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 etrailer.com or call 800-298-1624 for expert service.
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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 Reviews

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

Average Customer Rating:  4.8 out of 5 stars   (570 Customer Reviews)


- 30717
by:

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.



- 30717
by:

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.


Comments
Item # 18138
Mounting Bracket for 7-Way
$5.95
is the mounting bracket that works with this wiring.
-- Etrailer Expert Sierra K - 12/01/2021


- 30717
by:

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!



- 30717
by:

Installed the wiring harness for 2021 Toyota Tacoma. Everything went together just as noted in the instruction.



- 30717
by:

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.



- 30717
by:

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.



- 30717
by:

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!



- 30717
by:

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.



- 30717
by:

Had a great experience ordering from etrailer. Product arrived fast and customer service was excellent.



- 30717
by:

Yes, very nicely designed wiring harness. Works Great....



- 30717
by:

Kyle was extremely helpful in not only finding the right hitch but the accessories I needed to go with it. Would definitely recommend etrailer.com to all my friends. Prices were excellent too!



- 30717
by:

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



- 30717
by:

Worked as intended - wished they included a wiring diagram for us trailer newbies.



- 30717
by:

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



- 30717
by:

Works great. Easy install. It's 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!


Comments
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.
-- Etrailer Expert Laura E - 02/10/2017


- 30717
by:

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.


Comments
Im still enjoying this product, Ive used it several times, still workingwell
Rics49 - 04/06/2015



- 30717
by:

Install was really easy and seems to be holding up after 1 year well.



- 30717
by:

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



- 30717
by:

I was surprised how fast the shipping was and the price for the product was very reasonable. I did not mind that there was no mounting plate for the adapter because I wanted something that would hook up to the camper when I need to use it and then take it off afterwards. I know I will be coming to etrailer for any other trailer or camper needs that may come up.


Comments
could not be happier with the purchase that I made
Al N - 05/26/2016



- 30717
by:

Every time etrailer has provided me with the needed wiring!



- 30717
by:

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.


Comments
Had the same issue with the ground kurt. Almost gave up on it until I read your post. Thanks.
-- comment by: mike g - 06/17/2014

Comments
Thank you so much. Ours wasnt working either until we grounded it to car frame.
-- comment by: Sarah - 10/08/2015



- 30717
by:

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



- 30717
by:

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 etrailer.com.



- 30717
by:

Works great!



- 30717
by:

I was wanting to pull an enclosed trailer that has 7 pole plug in, with my vehicle that only has 4 pole plug in, without messing with the wires at this time, so I ordered the 4 pole to 7 pole adapter for this purpose. When item arrived I plugged adapter in, checked lights and on my way I went. all the extra wiring is there when I decide to add a brake controller. Now I can unplug the adapter and still use my 4 pole plug in. The item was well put together with tight wiring, price was reasonable, the shipping was smooth and the website is outstanding with plenty of instructions, wiring diagrams and the how to videos are a real plus on wiring up trailers. Thanks for an informative website and great product.


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Show More Reviews

Ask the Experts about this Tow Ready Trailer Wiring



  • Can a Adapter 4 Pole to 7 Pole Be Used Just for Tail Light Functions
    Yes, you could use this Adapter 4 Pole to 7 Pole Vehicle End Trailer Connector # 30717 to adapt from a 4-way to a 7-way. You could simply tie they wires you would not use up and out of the way and you would be fine. You will still need to ground the white wire though. I attached an installation video for this product for you to check out also as well as an FAQ on trailer wiring for you to check out.
    view full answer...
  • Trailer Lights are Not Working with 4-Way to 7-Way Adapter Plugged Into 2011 Ford Escape
    For the adapter # 30717 to function, the white wire has to be grounded to the vehicle frame. Without that ground it will not function. If it is properly grounded and you still do not have lights on the trailer, make sure that the adapter 7-Way and the trailer 7-Way pin configurations match up. I have included a link to our wiring FAQ article that shows diagrams of how various connectors should be pinned. If you are still not getting lights test the 4-Way on the vehicle with a circuit...
    view full answer...
  • What are the Functions of a 4-Way Trailer Connector
    Trailers use a combined brake and tail light circuit (2-wire system). The left brake light and turn signal is with the yellow wire and the right brake light and turn signal is with the green wire. I have included a link to our FAQ on wiring for you that shows the functions.
    view full answer...
  • Left Turn and Brake Signal Does Not Work Using the Adapter 4 Pole and 7 Pole Connector # 30717
    The first thing that you will want to do is to use a circuit tester like Quickee Circuit Tester, # 3808, to test the pins for proper function at the 7-way connector, # 30717, that you just installed. I would recommend testing each pin for proper function. When looking at the 7-way connector, the drivers side brake and turn signal, or brake and left turn signal, pin should be the pin in the 9 o clock position. If all of the pins on the 7-way connector function appropriately, then you know...
    view full answer...
  • Dim and Malfunctioning Trailer Lights on a Trailer Towed by a 1988 Chevy C/K Series Truck
    This sounds like a weak ground, corroded connector, or both. Make sure that the ground on the 7-Way you installed is attached to a clean and corrosion free bare metal surface. A weak ground could cause this issue. Ground problems normally show up when there is more load on the system like when the running lights are on and you step on the brake. Also make sure the 4-way that you installed is properly grounded. A corroded connector can cause all sorts of weird things to occur as well so...
    view full answer...
  • Finding a Ground Location for a Trailer Wiring Harness on a Kia Optima
    You may need to scrape away some undercoating on the bottom of the vehicle in order to get a bare metal surface. Any surface with coating or paint will need to have those materials removed in order to get a good ground connection. Usually behind a tail light assembly there is some bare metal. You can also look for other wiring harnesses nearby and ground it in the same location.
    view full answer...
  • Testing Wires On a 1994 Jeep Grand Cherokee to Determine Functions to Install a Trailer Connector
    You cannot go by color because there is no standard for colors. You have to go by function only. To do this you will use a circuit tester like # 3808 and test the vehicle wires one at a time while someone sits in the vehicle and runs through all of the light functions. Then you can wire it all up following the functions (not colors) in the diagrams in the FAQ I have linked. On the trailer side, I assume the connector is fine. If the trailer is new then white is likely ground, brown is...
    view full answer...
  • Troubleshooting Left Brake Light Not Functioning on a Trailer Towed by a 2002 Town and Country LX
    I would suspect you are having a ground issue. Ground issues usually come out when the brake lights are being applied because both tail lights are drawing the most amperage at that point. I would check your trailer connector for corrosion and clean as necessary-as the problem is usually there or where the tail light assembly grounds. If the tail light assembly grounds through the installation hardware you will want to be sure they are installed on a clean metal surface. I attached an...
    view full answer...
  • Will Running the 12 volt Accessory Wire from a 7-way to a Trailer Battery Overcharge it
    The battery charging method that you described would not overcharge the battery of your trailer at all. Actually, at most it will put a very light maintenance charge on the battery to keep it topped off, but would not recharge the battery if it was fully discharged.
    view full answer...
  • How to Determine the Amperage on the 12 Volt Power Circuit in a Trailer Connector
    The amperage on the 12 volt power circuit will depend on the amperage draw of the item receiving the power on the trailer. When aftermarket 7-way trailer connectors are installed on vehicles, it is recommended to have a 40-amp circuit breaker inline on the power wire going from the trailer connector to the battery. If your truck has factory trailer wiring, there will be a fuse in the fuse box designated for that circuit. You can check your owners manual to see the names and locations of...
    view full answer...
  • Troubleshooting Trailer Lights That Flash with Blinkers and Don't work When Brakes are Applied
    First thing I would do is check for corrosion in the 7-way of your 2004 Chevy Avalanche and clean as necessary. Most of the time this fixes situations like this. Aside from that the other most common problem is bad grounds on the trailer lights. You will want to make sure the grounds on the trailer light assemblies are connected to a clean metal surface. Also, the ground strap that runs from the trailer 4-way to the trailer frame needs to be connected to a clean metal surface. Aside from...
    view full answer...
  • Can 4 to 7-Way Trailer Connector Adapter Be Grounded to Trailer Frame Instead of Vehicle Frame
    Since the 4 to 7-Way adapter # 30717 is a vehicle side connector it will be mounted on the vehicle. Grounding it to the trailer frame would mean you would have to disconnect that ground every time you disconnected the trailer from the tow vehicle. The trailer side connector already has a main ground connection so this one needs to stay grounded to the vehicle side.
    view full answer...
  • Right Turn Signal Not Working on 7-Way After Installing 4 to 7-Way Adapter # 30717
    Since the brake lights and turn signals are combined on the same circuit, one for each side (3 oclock and 9 oclock pins) the right turn signal not working on the 7-Way is a little strange but not without precedent. It is likely a ground issue. Make sure that the white ground wire on adapter # 30717 is attached to a clean and corrosion free bare metal surface. Also, make sure the vehicle side 4-Way is clean and free of corrosion as well. Since the turn signal functions on the 4-Way it...
    view full answer...
  • Where Do the Black and Blue Wires on 30717 Attach To on a 1999 Ford F-250
    If your truck has the brake controller port underneath the dash, then there will be some wiring towards the rear of the truck that you will need to splice into. The blue wire on part # 30717 needs to be spliced into the blue wire on the factory tow wiring. We have an instructional page that shows how this is done that I have linked to below. You can also splice the black wire on the 30717 into the orange wire on the truck for a 12V power source.
    view full answer...
  • Where Does the Black Wire Attach for Harness 30717 on a 2003 Chrysler Town and Country
    The black 12 volt lead on Adapter 4 Pole to 7 Pole Vehicle End Trailer Connector, # 30717, attaches directly to the battery on your 2003 Chrysler Town and Country. You will have to attach the black wire to a length of additional wire, like 10 Gauge Blue Primary Wire - per foot, # 10-1-1, under your vehicle and run that wire to the battery through a 40 amp circuit breaker, # PK54540.
    view full answer...
  • What is the Yellow Auxiliary Wire for on 4 pole to 7 Pole Adapter from Tow Ready Part 30717
    The black wire is the 12V hot power source that is usually used to maintain a trailer battery. The yellow wire, in some cases it is orange or purple, is for the center post which is usually wired for reverse lights or a reverse lockout on a boat trailer. If you do not need a reverse circuit, you can just tape the yellow wire up and out of the way.
    view full answer...
  • Where to Connect Blue Wire on 4-Pole to 7-Way Adapter Part # 30717 if Trailer Has No Electric Brakes
    If the trailer you are planning on towing does not have electric brakes, you can simply leave the blue wire on the 4-pole to 7-way Adapter, part # 30717 disconnected. You can bundle it up, and zip tie it up out of the way. If the trailer does have electric brakes, a brake controller would be needed to actuate them. The blue wire would be extended and ran under the vehicle to the engine compartment, and through the firewall to connect with the blue brake output wire on the brake controller. To...
    view full answer...
  • How to Find Brake Switch Wire in a 1978 Ford F-100 for Brake Controller Installation
    Are your vehicle brake lights still working when you press the brake pedal? If so, then it sounds like maybe you are testing the wrong circuit. It sounds like you could be installing a brake controller and are looking for the correct circuit to run to the stoplight circuit of the brake controller. If this is the case keep checking the circuits you found near the brake pedal till you find one that has 12 volts when the brakes are pressed and none when released. For more information on...
    view full answer...
  • Wiring Adapter 4 Pole to 7 Pole Vehicle End Trailer Connector
    You could wire the Tow Ready Adapter 4 Pole to 7 Pole # 30717 without the brake functions and just have the light functions on your tow vehicle without connecting the other wires. But I would be very cautious about not doing so for several reasons. The main reason is safety. The general rule for towing trailers with brakes is that if the Gross Trailer Weight is half of the Gross Vehicle Weight it is recommended to use a brake controller and have brakes on the trailer. Not being able to...
    view full answer...
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  • Can Extra Wires of the 4-Way to 7-Way Adapter 30717 be Taped Up If Not Needed
    If the surge brakes on your trailer do not have an electric reverse lockout then you could just tape up all of the wires that you didn't need of the # 30717 and you would be good to go. If the trailer does have an electric reverse lockout you would need to run the yellow wire to the reverse light circuit of your trailer and then also ground the white wire and you would be good to go.
    view full answer...
  • Does the Brake Output and 12 Volt Accessory Wires of the 4-Way to 7-Way Adapter Need to Be Run
    If your trailer does not have trailer brakes and all you need are taillight signals you would not need to run any additional wire to install and use the # 30717 on your vehicle. Just plug in your 4-way and you would be good to go.
    view full answer...
  • Does Every Wire of the Adapter 4 Pole to 7 Pole # 30717 Have to Be Run
    The yellow wire of the 7-way adapter part # 30717 is an aux. circuit that typically gets used for reverse lights. If you have no use for that circuit you would not have to hook it up. You could then just tape it up and out of the way.
    view full answer...
  • Will Camper Fridge Drawing Power from Hybrid Battery Damage the Battery on a 2007 Toyota Highlander
    If the 12 volt circuit on the 7-Way is connected to the main hybrid battery that powers the drive wheels on your 2007 Toyota Highlander then you would need to be careful about how much power items are pulling from it. Things with low power draw such as LED lights are not going to be an issue. But a refrigerator compressor can use a lot of amperage and that could potentially be harmful to a hybrid battery. What I recommend is to have the 12 volt circuit from the 7-Way just go to the trailer...
    view full answer...
  • Troubleshooting Running Lights That Go Out When Brake Lights Are Activated
    It sounds like you may have a weak ground connection on your vehicle's trailer wiring harness. A bad ground can cause all sorts of odd effects, including having one light function go out when another is activated. A weak ground will pass enough current for some functions to work, but possibly not for others. Check that the wiring harness ground wire's ring terminal is tightly attached at a clean bare metal surface on the vehicle. You may want to clean/sand that spot to ensure metal-to-metal...
    view full answer...


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