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Adapter 4 Pole to 6 Pole and 4 Pole Trailer Wiring Adapter

Adapter 4 Pole to 6 Pole and 4 Pole Trailer Wiring Adapter

Item # 37175
Our Price: $37.62
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Trailer Wiring
Shipping Weight: 0.83 lbs
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37175 - Plug and Lead Hopkins Wiring Adapters
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Great Prices for the best trailer wiring from Hopkins. Adapter 4 Pole to 6 Pole and 4 Pole Trailer Wiring Adapter part number 37175 can be ordered online at or call 1-800-940-8924 for expert service.
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  • Reviews (59)
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Hopkins Trailer Wiring - 37175

  • Wiring Adapters
  • Multi-Function Adapter
  • 6 Round
  • 4 Flat
  • Plug and Lead
  • 4 Flat
  • Hopkins

Adapter converts from 4 pole wiring on vehicle to 6 pole round plug and 4 pole flat. Additional wire leads for brake and an accessory.

  • 4 Pole to 6 pole and 4 pole vehicle side trailer wiring adapter
  • Includes mounting bracket
  • Includes 3 wire leads
    • Blue - for electric brakes - center pin
    • Red - for auxiliary or hot lead - outside pin
    • White - for the ground

Note: The white wire must be grounded to the vehicle frame. The other two wires can be tied up if they are not going to be used.

47175 Adapter 4 Pole to 6 Pole and 4 Pole Trailer Wiring Adapter

California residents: click here

Video of Adapter 4 Pole to 6 Pole and 4 Pole Trailer Wiring Adapter

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

Video Transcript for Hopkins Wiring - Wiring Adapters - 37175 Review

Today we're going to be taking a look at the Hopkins Wiring Adapter. This adapter converts your vehicle from just a four pole flat to a six pole round and a four pole flat. It's going to provide additional wire leads for brake and for power. It's going to come with your mounting bracket and it's going to come with the necessary hardware to get that installed. This set of hardware over here, this is going to actually be to get the connector installed onto the bracket. This set of hardware right here would be to get the bracket installed onto the vehicle. You notice the wires that we have coming out the back here. We're going to have a red wire with a butt connector attached to it.

That's going to be for auxiliary or hot lead. That's the outside pin. You're going to have a blue wire with a butt connector on it, that's going to be for your electric trailer brakes. That's going to be a center pin connection, and then you're going to have a longer wire. This is your white wire.

It has a ring terminal attached to it and that's going to be for your ground. Now each lead, again it's going to have connectors on it that's going to make connecting very quick and easy. Please note that the white wire must be grounded to the vehicle frame. The other two wires can be tied up if they're not going to be used. You can wrap them up in tape and zip tie them to the frame so they're up and out of the way. Those are optional, but again they are pre-wired into the six pole connection, or the six pole connector in case your application needs to use those. Again red is going to be power lead or auxiliary, and blue is for your electric brakes.

It's also a good idea to use some grease on your connection points to help prevent corrosion. Right here on the connector you're going to have a flap that has a nice spring lid on it. It also has a seal on the inside so it's going to keep out dirt and moisture. That's fully opened so you can easily make your connection there for your six pole. Then on this side you're going to have a dust cap that's going to cover up the four-way connector. That's going to do it for today's look at the Hopkin's wiring adapter.

Again the adapter's going to convert your vehicle from just the four pole flat to a six pole round and a four pole flat connector.

Customer Satisfaction Score:

Customer Reviews

Adapter 4 Pole to 6 Pole and 4 Pole Trailer Wiring Adapter - 37175

Average Customer Rating:  4.8 out of 5 stars   (59 Customer Reviews)


This adapter really cleaned up the installation and connected directly to the wiring harness. Maybe added an additional 20 mins to install this adapter but totally worth the time and money.


II use it on my towed vehicle behind the motor home. It allows me to take motor home power to a trickle charger in the towed vehicle and connect to the towed vehicle wiring. The four prong receptacle provides outlet to be used if there is ever in need for a four prong fitting good.



Works well but bracket is rusting


Pulled our popup camper all over Michigan from Tawas to Drummond Island with no hickups with lighting. We also pull a smaller trailer with the four prong plug, also with no problems. Its nice that these plugs stay covered so as to not let salt/grime into plugins. Great products in my opinion. Had for just over one year with no problems at all. We had these installed by local reliable installers and wouldn't change anything.


Draw-Tite 75726 hitch fit perfectly and looks great.
Instructions from manufacturer regarding 2013 Highlander driver's side splash panel removal and then not use: it was easy to cut an 8" longer slot in the splash panel and reinstall, which retains the bumper and fender integrity.

The 37175 4 & 6 pole adapter is a clean look and very handy using the different trailer hookups.

The 118449 T wire harness hookup is a no hassle, no brainer and works perfectly

Etrailer will my business on my next vehicle needing towing equipment!


The adapter was easy to install and looks great on my 2011 Toyota Corolla. It allows me to tow my small motorcycle camper and my utility trailer with the car, truck or the motorcycle without changing the existing wiring on either one. Etrailer shipped the order in very good time and kept me informed of the order status until it arrived a my door.


This should have been an easy install, but it wasn't. There is nothing wrong with the part and should work well in most situations. However, in my situation, I installed the Curt Class III custom hitch which allows for keeping the full size spare tire. Unfortunately for installing this part, there was no room if the mounting bracket was used - the hitch was in the way.

So, I drilled a hole through the bumper and installed it there. This took more time than the instructed install, but in the end it works great and there is no worry of wires rubbing or wearing through. See picture.


We have had our hitch and wiring harness for about a year now and its still performing great. This site sells great products and we will definitely be back to buy more when ever we need it!


This item was used to reair an existing unit mounted on my Toyota Tacoma. Although it initially worked very well I thought the 4 pole connector was not sturdy enough for my use. After having a pin break out when the plug was snagged I changed to the 6 pole connector and have been very satisfied.


This kit was an excellent addition to the general hookup kit as it provides wiring options for different trailers and is very simple to install, including excellent instructions. I highly recommend this kit.


Product was easy to install. Comes with bracket, which is nice, but I didn't use, had a place already built in to the hitch. Had it installed in less than 10 minutes. e-trailer kept me informed through the whole shipping process, and they have great how-to videos.


This is my second purchase from ETrailer. The product I ordered shipped out on time and arrived in good condition. The folks at ETrailer set me out a shipping tracker and notifcation.....very helpful! I would recommend ETrailer to anyone looking for trailer parts or accesories. Products are high quality and prices are great! Keep up the good work!


I installed this on an aftermarket replacement bumper I bought after someone collided with my factory bumper (thank you very much whoever you were). Installation was a snap into the pre-drilled hole in the bumper. Just used some dielectric grease on the contacts, wrapped with electric tape, zip-tied to secure, and did a quick tap into the frame for the ground.


Great product that works well with the standard wiring harness for the car. This worked great with my 1963 Aloha trailer that uses the 6 pin configuration.


Ordered a 4 to 6 pole trailer wiring adapter. It was perfect, as was the service, delivery time and follow up.


Always amazing every time I purchase from here. Fast shipping Way to go


This product is great and works good, easy to install, fits ext. wire harness like a glove.


eTrailer is a great company that sells good products at a reasonable price. In addition, they are very helpful in selecting products and providing post sale support. As for the product... it’s just what I was looking for. Perfect!


Works like a charm. Wired to connect to motorhome. All features working.

Keith C.


Installed it, connected it, its working just as it should


This plug is exactly what I needed. And for a good price. Easy installation. Saves the work of having to do all the wiring when I already have a flat 4 plug


the wiring works fine but the spring does not hold the cover closed on the 6 pole side. i tried bending the spring but when you open it up it re bends the spring. mine could have been a defect but would have given 5 stars if it wasn't for the spring


This was the perfect harness for my vehicle. Installed easily and has made a great deal of difference. Excellent customer service as well.


Product shipped quickly and was exactly as described. It mounted to my Wrangler in just a few minutes of work.


A perfect replacement for a damaged plu g.


Quickly shipped and great value. Very easy to mount and saves time by having two plugs available and not having to switch when using round plug. Great seller and very good product.


The product is ok, the only problem is the spring of the plastic cover of the plug is not strong enough to close the hole. After few times open/close it gets loose...(not close tight)

Show More Reviews

See what our Experts say about this Hopkins Trailer Wiring

  • Wiring a Trailer with a 6-Pin Plug and Surge Brakes to a 2004 Dodge Ram with a 4-Way Connecter
    Typically, a trailer with a 6-way plug has electric brakes, not surge. I would double check that you have surge brakes and that your plug is a 6-way. A 6-way plug is circular, has 5 pins on the outside and 1 pin in the middle. If you do have a 6-way with surge brakes, you will need the Adapter 4 Pole to 6 Pole, part # 37175. You will have 3 loose wires coming off of the adapter. You will ground the white, and then you will have to wire one of the two remaining wires into your reverse light....
    view full answer...
  • Where Does the Brake Controller Output Wire Terminate on a 2008 Dodge Ram without OEM 7-Way
    On a 2008 Dodge Ram that did not come with a 7-Way trailer connector the brake controller output wire does not run all the way to the back of the truck. It stops at the connector that is located under the driver's side wheel well. I have linked a help article that covers this and other steps. But if you have a factory 7-Way then you would not need to worry about that because the wire would be run all the way back.
    view full answer...
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  • Difference Between Hopkins 4 Pole to 6 Way Trailer Connector Adapter 37175 and 47175
    There is no difference between the # 37175 and the 47175, it's the same exact part. Our part number for the Hopkins 4 pole to 6 way trailer connector adapter is # 37175, and Hopkins uses 47175 as the part number.
    view full answer...
  • Adapter for a 4-Flat on 2000 Ford Expedition and 6 Round on Trailer
    From your description, it sounds like you are looking for a way to use the factory 4 flat on your 2000 Ford Expedition with the 6 round on your trailer. If that is the case, what you would want to do is use the 4 Pole to 6 Pole Wiring Adapter # 37175. I have added a pair of links to videos reviews of this adapter for you to take a look at.
    view full answer...
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  • Is Adapter 37175 a Specific Fit For Any Vehicle
    The Adapter 4 Pole to 6 Pole and 4 Pole Trailer Wiring Adapter # is actually not a vehicle-specific fit, which means it can be used on any vehicle as a way to give it a combination 6-round and 4-flat on the vehicle. Once hardwired in, this will let you tow a trailer that has either a 6-round or 4-flat (the difference being the 6-way has two additional pins compared to a 4-way, for a brake controller output and 12 volt power). I have added a link to a video review for this adapter, as well...
    view full answer...
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  • Adapter Recommendation to Go From 4 Pole Flat to 6-Way Round
    The Hopkins adapter part # 37175 that you referenced is the style of adapter that you mentioned. It goes from a 4-way flat connector to a 6-pole round like what you are looking for. I attached a review video for this for you to check out as well.
    view full answer...
  • Can the Blue or Red Wire On the Adapter 4 Pole to 6 Pole Be Used For Reverse Lights
    In regards to the Adapter 4 Pole to 6 Pole and 4 Pole Trailer Wiring Adapter part # 37175, the blue or red wire could be used for reverse lights. That said, you would just need to be sure you hook the reverse lights up on the trailer side connector to the adjacent pin. I have attached a photo that shows how the pins on a 6-pole should be wired but so long as the vehicle and trailer side both match the orientation does not matter.
    view full answer...
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  • Hopkins Wiring Harness # Recommendation for a 1994 Toyota Previa Van
    Yes, you could plug the Adapter 4 Pole to 6 Pole and 4 Pole Trailer Wiring Adapter, part # 37175, into the 4-way of the Tow Ready Wiring Harness, part # 119178. As long as you do not need any of the other functions that the 6-way has you would not need to wire up those wires to the # 37175. The 6-way would essentially be a 4-way, except it would be through a 6-way connector, and you could wire up the rest of the wires later if you changed your mind. I attached a video of a # 119178 being...
    view full answer...
  • Does Adapter 4 Pole to 6 Pole and 4 Pole Trailer Wiring Adapter # 37175 Use 10 Gauge Wire
    The Adapter 4 Pole to 6 Pole and 4 Pole Trailer Wiring Adapter # 37175 has 10 gauge wire for the blue wire, red wire, and black wire. The aux circuit you mentioned would be the black wire.
    view full answer...
  • 4 Way Flat to 6 Pole and 4 Way Adapter for Trailer Wiring
    Yes, we do have an adapter for you. The Adapter 4 Pole to 6 Pole and 4 Pole Trailer Wiring Adapter # 37175 is what you are looking for. You may also want to pick up some Dielectric Grease for Electrical Connectors # 11755 for installation if you don't already have some.
    view full answer...
  • Adapting 4 Pin Trailer Connector on 2005 F150 to 7 Pin Connector on Horse Trailer
    If you really like this truck, adapting the 4-way to work with the connector on the horse trailer is pretty simple. Your truck already has the connection port under the dash for a brake controller, and the output wire for the brake voltage will be run to the rear of the truck along the drivers side frame rail. Its a blue wire, and usually terminates near the back wheel. Are you sure that the horse trailer has the 7-way blade connector? Horse trailers typically have the 6 pin. In any event,...
    view full answer...
  • Will the 4 Pole to 6 Pole to 4 Pole Trailer Wiring Adapter Work For My Trailer
    The Hopkins 4 Pole to 6 Pole Trailer Wiring Adapter # 37175 will work to connect your vehicle wiring to your trailer wiring. However, you will need the Wiring Kit for Brake Controllers # 5506 to make the adapter fully functional. The 6-way adapter has three wire leads: the blue is for electric brakes, the red wire is the hot lead and the white wire is the ground wire. I attached installation videos of the wiring adapter and wiring kit you may want to check out. There are two standard wiring...
    view full answer...
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  • Recommended 4-Way Vehicle Side To 6-Way Round Trailer Connection
    The adapter you need is the Hopkins Adapter 4 Pole to 6 Pole and 4 Pole Trailer Wiring Adapter # 37175. This will take your 4-way flat on your truck and allow you to convert to a 6-way round. This will give you wires for the remaining two functions to match your trailer. If you are just looking to match 4-way function, there is nothing more to do. If your trailer has brakes, you can use the brake controller wiring # 5506 along with a brake controller like # 90195 to give you a fully...
    view full answer...
  • Parts Needed to Wire Up 6-Way on 2001 Toyota Tacoma
    Normally in a situation like this the best way to accomplish adding a 6-way round to a 2001 Toyota Tacoma is to first use a 4-way kit like part # C55379 to get the correct signals combined and then use an adapter like part # 37175 to convert it to a 6-way. Since you have a 6-way ready to wire up best option would be to use the # C55379 to get the circuits combined like you are needing and then cutting off the 4-way of the kit and wiring the circuits to the 6-way.
    view full answer...
  • Location of Ground Wire Connection on 6 Pin Trailer Connection on 2001 Chevy Silverado
    For a 6 way round connection, like you find on the Hopkins Adapter 4 Pole to 6 Pole and 4 Pole Trailer Wiring Adapter # 37175, the ground wire will be located in the 2 o'clock position as you face the connector. The back of the connector (10 o'clock position) will have the ground wire which will be connected to the frame of your vehicle and should have a bare metal to metal connection. I've attached a photo and an article to assist. If you have a 7-way and need to have a 6-way connection...
    view full answer...
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  • Parts Needed to Adapt a 4 Pin to a 6 Pin Round
    Yes, it is possible to change your 4 pin to a 6 pin round. I recommend using the Adapter 4 Pole to 6 Pole and 4 Pole Trailer Wiring Adapter # 37175. This would allow you to have both the 4 pin and 6 pin round. I have included a video that shows an installation of the # 37175. You will want to pick up some Dielectric Grease # 11755 and the No-Drill Mount Bracket # 18136 for installation.
    view full answer...
  • Wiring Adapter for Charging a Trailer Battery with a 2008 Subaru Outback
    Using the existing 4-way connector to power your battery is not possible, as each circuit on that connector will already be used for the trailer wiring. Your trailer has what we refer to as a 7-way trailer connector (6 slots plus the center pin). We offer an adapter, part number 37185 that will convert your existing 4 pin connector to the 7-way. These connections are standard, but to power the trailer battery, you will need to run a wire from the black lead on the adapter to the vehicle's...
    view full answer...
  • Will Adapter # 37175 Fit a 2005 Honda Pilot and a Coleman Tent Trailer
    Yes, the Adapter 4 Pole to 6 Pole, # 37175, is compatible with the 4-Way flat on your 2005 Honda Pilot and the 6-Pole on your camper. The adapter has 3 additional wires that will need to be attached on the vehicle side. Thewhite wire must be grounded to the vehicle frame. The remaining 2 wires are optional if needed. If not needed, they can be taped up and stowed out of the way. The blue wire is for electric brakes and would connect to a brake controller in the vehicle cab. The black wire...
    view full answer...
  • What Wiring Changes do I need to Make for LED Lights on My Trailer
    Because LED running lights use much less power than their incandescent counterparts, you should not be in any danger of overloading anything. Because of that, and because your truck already has the 4 pole connector, you do not need a converter. Your signal is already converted. You can certainly use a 4 to 6 pole adapter, part # 37175 or a 4 to 7 pole adapter, part # 37185. The powered accessory lead would use the black wire on the 7 way adapter and the blue wire on the 6 way. You would...
    view full answer...
  • Will the 4-Way to 6 Pole Adapter # 37175 Fit a 2000 Ford F-150 with Factory 4-Way
    The protective cover on the Adapter, # 37175 should not interfere with the standard 4-Way on your 2000 Ford F-150. It may be snug at first but you do want a tight connection. I have included a link to a video review of this harness for you. In order to make the 6 pole fully functional, you will need to hardwire in the remaining wires on the adapter. You must ground the white wire to the vehicle frame using the white wire on the adapter. The blue wire will connect to a brake controller....
    view full answer...
  • Brake Controller 6 and 4 Way Installation Kit # ETBC7 for a 1993 Ford F250
    Since you have a 4-way connector on your 1993 Ford F-250 and you need a 6-way round for the trailer I would recommend that you install a Brake Controller 6 and 4 Way Installation Kit, part # ETBC6, on your F-250. This will convert your 4-way to a 6-way and allow you to connect to the trailer you are purchasing and use a brake controller if you have one. If you need a brake controller I would recommend a Tekonsha Brake Controller, part # 90885. I attached installation instructions for you...
    view full answer...
  • Brake Controller and Wiring Recommendation for a 2008 Ford Explorer Towing Trailer with 6-Way
    The part # 37175 could be used to adapt your 4-way to a 6-way, but you will be required to track down several other components so that you can make the connector functional and to install a brake controller. A better product to get would be the part # ETBC6 as it comes with everything needed to convert the 4-way to a 6-way and wire up a brake controller. I attached a link to install instructions plus an install video for you to check out. I also attached a picture that has a diagram that...
    view full answer...
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  • Is There a 6 and 4-Way Combo Connector Sold Separately for Use on a 1998 GMC Ck Series Pickup
    Yes, we have an adapter that converts the 4 pole connector to a 6 and 4-way connector, it is Adapter 4 Pole to 6 Pole and 4 Pole Trailer Wiring Adapter, part 37175. If your vehicle currently has 4 pole wiring it will work perfectly on your 1998 Chevrolet CK Series Pickup Truck. If you do not have a 4-way connector on your vehicle you would need the Tow Ready Custom Fit Vehicle Wiring, part # 118315, that will plug directly to your factory wiring.
    view full answer...
  • Wiring Adapter for 4 Flat From an RV to 6 Pole Vehicle
    The Adapter 4 Pole to 6 Pole and 4 Pole Trailer Wiring Adapter, # 37175, is the correct adapter for this application. Basically, you plug your RV wiring into the 4 Flat side of the 6 Pole and wire the two extra circuits needed into the RV wiring. You will also need two extra wires, Jacketed 2 Wire, 10 Gauge, Brake Wire - per Foot, # 10-2-1, if your towed vehicle requires the extra circuits. The two extra circuits could be for any number of applications such as tow vehicle braking,...
    view full answer...

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Employee Jameson C
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