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Adapter 7-Pole to 4-Pole and 5-Pole

Adapter 7-Pole to 4-Pole and 5-Pole

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Adapter 7-Pole to 4-Pole and 5-Pole Multi-Function Adapter 37385
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Great Prices for the best trailer wiring from Hopkins. Adapter 7-Pole to 4-Pole and 5-Pole part number 37385 can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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  • Reviews (115)
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  • Videos (2)
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Hopkins Trailer Wiring

  • Wiring Adapters
  • Multi-Function Adapter
  • 4 Flat
  • 5 Flat
  • Plug Only
  • 7 Round - Blade
  • Hopkins


Features:

  • Wiring Adapter - converts the 7-way trailer connector on the vehicle to a 4-way or 5-way connector to match the trailer


If your truck has the connector on the left, and your trailer has one of the connectors on the right, you will want this adapter.
30300 18004
Vehicle End Trailer Ends


47385 Adapter 7 Pole to 4 Pole and 5 Pole - TAP # 37385

Item # 37385




California residents: click here


Video of Adapter 7-Pole to 4-Pole and 5-Pole

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




Video Transcript for Hopkins 7-Pole to 4-Pole and 5-Pole Adapter Review

Hey everybody, Ryan here at etrailer. Today we're gonna be checking out the Hopkins trailer wiring adaptor plug. So this is gonna go from a seven-way round not only to a four-way flat, but also a five-way flat. So let's check it out. And if your vehicle has a seven-way round type connector like mine does here, and you have to tow a trailer that has a four-way flat or five-way flat, this is gonna allow you to do that. So the way this will work is you'll plug into your seven-way round connector and then choose the appropriate type of wiring.

So we're hooked up to a small little fishing boat here. It has a four-way flat. We can open up that cap, take our trailer wiring, and plug right into it, and that's gonna allow all the signals to transfer back to our trailer, giving us all the lighting signals to keep us safe and legal. And what a lot of people like about this one is this honestly gives you the ability to tow or hook up to, wiring-wise, just about any trailer. So let's say maybe you have a utility trailer that has a four-way flat and then maybe a boat trailer that has brakes or something on it that has a five-way flat.

Having this one adapter is gonna allow you to pair up to all those different types and not have to keep two or three of these rolling around in your glove box or whatever the case is. These signals that this is gonna send back for our four-way flat will be your taillights, your brake lights, and your turn signals. So you have all your bases covered there. Five-way flat is gonna send out all those same lighting functions except that fifth pen is gonna be for a reverse light or backup circuit. Generally you'd see that on marine or boat trailers that are a little bit larger that have surge brakes, or even if maybe you have a utility trailer and you want to set up reverse lights on it, something along those lines.

That's where the five-way flat is gonna come into play. As far as the construction quality goes, I feel like it's pretty well-made. Feels like it's thick plastic, don't feel like a piece of junk by any means. It does fit nice and tight, at least into my seven-way. So that's good.

You know, don't worry about it having a loose connection or something, but I like how they give you the caps too because if you want to leave this thing in here, say if you tow a lot or something, or just don't feel like storing it inside the vehicle, at least you can keep those terminals protected against corrosion and whatnot. And honestly, from time to time anyway, it's not a bad idea to apply di-electric grease to 'em. And that holds true for your trailer end as well. Just keeps it in better shape and you can expect to get a little more life out of it. Something that I have ran into the past with using certain types of adapters is every trailer end might be a little bit different. These you don't see too often, but they are out there where they're kind of boxed in and in the past I've had issues getting 'em to hook up. And with this particular one, that's really not the case. It still fits right over it and creates a good tight seal. We do have a trailer here that has a five-way flat. And just to kind of show that off, you don't want to give the four-way all the love today. We'll just show you how it works too. You know, pretty standard connector and don't run into any issues in terms of getting that plugged in into our adapter plug. Other than that, at the end of the day, you know a great solution for those of you that have different types of trailers or different types of wiring, or if you're just unsure of what you might be pulling in the future. This is gonna allow you to hook up to all those different types for the most part. So can't really ask for too much more. But that'll about do it for our look-at of the Hopkins seven to five and four-way adaptor plug.

Customer Satisfaction Score:


Customer Reviews

Adapter 7-Pole to 4-Pole and 5-Pole - 37385

Average Customer Rating:  4.8 out of 5 stars   (115 Customer Reviews)


by:

You don’t often run into a flat 5-pole connector, but it’s nice to have it covered!



by:

The 4/5 flat adapter arrived as described. Very good quality.



by:

Wish I would have found this earlier, Super addition to my towing kit in my Atlas



by:

Great service.



by:

In my quest for a 7 pin to 4 pin connector to operate lights on my luggage rack my search led me to etrailer. Initially I spoke with Derek who was very helpful and sent me a connector that was 7 to 5 pin as that's what I thought I had. Turns out I was wrong so I called back to order a 7 to 4. This time I found Ashley and she quickly mailed me the 7 to 4.
These two employees were most helpful and very courteous in my dealings with them I'm happy to recommend etrailer for these kinds of products. Give them a try!

Jim L.

7/29/2018

Works fine. Only used it a few times but no problems.



by:

These plugs work great. I use it for my boat trailer (5 Plug), Jetski trailer (4 Plug) and a Car Hauler Trailer (7-way). Very simple to use. Highly recommend it you use multiple trailers with different plugs and braking systems.

Ted

9/10/2020

Everything is still working great with no issues!!



by:

Product was delivered in a timely fashion and matched the part ordered. Quality was excellent and provided the features per price point that was desired. So far, no problems in use. It is now part of my basic trailering kit. Other products are available that have more features but they are larger and cost more. For my use this is right on. Product support and useful information from etrailer is consistently excellent.

Capt.wanabe

7/23/2018

After one year the wiring adapter continues to work well. I would not change my original review.



by:

Provides a quick and simple solution for connecting a trailer with a flat-4 or flat-5 plug to my truck with its round 7-way plug.

Robin N.

7/21/2017

We recently towed a rental trailer from Maryland to New Mexico. This connector worked perfectly!



by:

Works well.



by:

The adapter fit tightly and worked well. Be careful attaching and detaching the trailer harness so, you don't bend the bottom metal, male connector.

Everything installed correctly the first time and worked on my 2011 Honda Pilot. What a relief. It took me about 2.5 hrs because, I had to figure out fasteners for the bumper, existing wiring harness, etc. so I didn't break anything. Make sure you have a center punch, sharp metal drill bits and oil to pilot holes for self tapping screws. I am very happy with the harness and adapter.



by:

Exact replacement for the one I lost, had no problem finding it at etrailer since I had previously bought hard to find parts I needed when replacing worn parts on my boat trailer. Thanks etrailer.

Jimmy

4/7/2019

Working great, I am causious about not losing it again, thanks again.



by:

Well made and reasonably priced.



by:

Was exited when I found this on etrailer's website...I have 2 different trailers with 2 differents light harness connectors. This works great...no need to switch out or have two or more adaptors in truck!! Highly recommend!



by:

Overall...much better than going through the dealership for the sake of time and money. The online videos hit all they key points and steps bit there was some mechanical ingenuity required on my part. Mounting the bracket was the most challenging part to install and it was correctly represented in other reviews.

Personally, I wanted the 7 pin connector flush to the bumper and had to bend the mounting bracket and cut out the plastic bumper to get a tight fit. Looking back however, I think that if I would have cut out just enough of the bumper to accommodate the angle of the mounting bracket (when attached to the frame) then I would have still achieved both a solid connection and clean, professional look.

All in all, I'm very satisfied with the product and instructions received from e Trailer and staff.



by:

It was great and worked exactly as it was supposed to until my dog pulled it out of the receptacle and chewed it to bits.
I put an external tire carrier on my car and was using the three hole side to power my relocated license plate.
The rig lasted through all sorts of weather and terrain like a champ. I got about 9 months out of it before it was devoured. I'm sure it would have lasted for years if not for the >-< dog.



by:

This adapter works perfect. It easily installs into the round 7 pin connector. The connector worked as all lights were lit and I was able to back my boat trailer into position with no problems. The 5 flat is used for the inclusion of the surge brakes on my boat trailer. I would recommend this to anyone needing the conversion adapter.



by:

Good product. Works well and is very convenient to have both 4 and 5 pin connectors. Only issue is dust cover on 5 pin sticks to ground pin when you pull it off with the tab and can bend the ground pin.



by:

The Adapter made a quick and easy connection between my truck and the trailer. All lights functioned properly.

Great adapter at a great price.



by:

The wiring kit fits perfectly. I had a small problem with the operation of the brakes on my trailer but a quick call to the great service department and my problem was quickly rectified. I will do business again.



by:

Fits the round plug on the vehicle perfectly. Haven't hooked it up to the flat wire yet, but assume it should be fine. Getting this adapter with the covers for the 4 & 5 flat is absolutely the right way to go. I'm towing a 5500 lb boat with surge brakes.
Jesse did an outstanding job of helping me.



by:

As always, product arrived quickly and well-packed. Good quality and is working well on my vehicle. etrailer can be counted on for quality and customer service.

David

3/28/2020

No problems, never give it a second thought. Can depend on it to do the job.



by:

This trailer light adapter allows me to haul 2 different trailer with one vehicle. Delivery was in 3 days and I also purchased a 5 wire trailer wiring harness to match



by:

Just what I needed, have a boat and two wheel trailer with different plugs , ordered the weather tech mud flats also for my 2011 gmc 1500, they were easy to install and look great, all items where to me in three days. Great job etrailer



by:

I'm not one to take the time to write reviews but I just got to say this company really impressed me with the information available on their site and with the terrific service when calling them on the phone. In my experience this level of customer service is very hard to find today. Keep up the great work and thanks again for your time and help. I'll definitely recommend you and will be back should I have any needs in the future!



by:

I find this adaptor to be very useful as I own and frequently tow, different size trailers all with different plug connectors. Nothing is worse than not having the right connection to make your trailer connection.


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Show More Reviews

See what our Experts say about this Hopkins Trailer Wiring

  • Troubleshooting No Brake Signals on Vehicle 4-Pole Wiring Harness
    In 4-pole trailer wiring the stop light signals are combined with the turn circuits on one circuit for each side of the trailer. Typically a yellow wire carries left stop/turn signals and a green wire carries right stop/turn signals. Please refer to the linked photo of a 4-pole that shows these function and pin assignments. If you are using a wiring adapter like the 7-Pole to 4-Pole and 5-Pole # 37385 you can remove it and test the 7-way socket on the vehicle to ensure the stop light signals...
    view full answer...
    Image 1 for Image 2 for
  • Utility Trailer Lights Work when Vehicle is Off But Stop Working When Vehicle is On and Running
    There could be a problem inside the vehicle or trailer side connector. You will need to make sure that each is clean and corrosion free inside and out. If your vehicle has a 12 volt circuit at the trailer connector that is only one when the truck is on, and it is shorting out due to corrosion, that could be the cause of the problem. It could also be a ground issue. Ground problems normally show up when there is more draw on a system such as when you have the running lights on and then...
    view full answer...
  • How To Wire For Lockout On Titan Coupler To Vehicle With 7-Way And Trailer With 4-Flat
    To connect the electric lockout on the Dexter Trailer Coupler, # 099-175-20, to your truck you will need to make sure the center pole of the 7-Way connector on your vehicle is wired to the reverse light circuit. If it is not wired to the reverse light circuit you will need to splice into the reverse light circuit behind the vehicles taillights and wire to the center pole inside your 7-Way vehicle connector. Once the 7-Way connector has the reverse light circuit at the center pole then...
    view full answer...
  • Adapter from Vehicle 7-Way to Two 4-Way Flat Connectors
    We actually do have an adapter that will accomplish just what you're needing! The Hopkins Adapter # 37385 goes from a 7-Way to a 4-Way and 5-Way combination. I reached out to my contact at Hopkins who said you can use both of those connections at the same time. All you need to do is plug one of the connectors to the 4-Way and then simply line up the ground pins on your 2nd 4-Way and the 5-Way for this to work. The ground pin is the one that is different from the rest.
    view full answer...
  • Why Would Camper Stop/Turn Signals Not Work but Running Lights Would
    Since both sides of the stop/turn signals stopped working that would indicate to me you have an insufficient ground that can't keep up with the amperage draw of the stop/turn circuits. So I would recommend checking the grounds of the light assemblies and also the ground strap from the main trailer connector to make sure it's making a solid connection to clean metal. I also attached a help article on troubleshooting trailer wiring for you to check out as well.
    view full answer...
  • No Turn or Brake Signals While Towing With 2018 Ford F-150 After New 7-Way Installation
    When you say receiver I believe you mean a trailer wiring connector. The trailer connector does need to be grounded to a clean bare metal surface of the truck's frame which is most likely causing the issues with the lights. Another thing to check for is any corrosion on the pins or bent pins of the trailer connector which may be causing a bad connection. If there is corrosion you can lightly sand it off but it sounds like you have a classic ground issue especially since you said the trailer...
    view full answer...
  • Troubleshooting Trailer Running Light Circuit Fuse Blowing with Trailer Connected 2005 Chevy Tahoe
    Sounds like the running light circuit is drawing more power than the trailer running light circuit of your 2005 Chevy Tahoe can handle. The best solution for this is to swap some(or all) of your running lights on your trailer for LEDs. LEDs draw a fraction of what an incandescent bulb draws. I attached a page that has all of our LED trailer lights for you to check out. There could also be a short on the running light circuit of your trailer. Start at the connector and clean/fix any corrosion...
    view full answer...
  • Adapting 2010 Ford E-350 With 4-Pole Wiring Harness to Tow Boat Trailer With 5-Pole Flat Connector
    There are several ways to adapt your different tow vehicle and trailer connectors. The most cost-effective method to put a 5-pole flat connector on your vehicle is to use Hopkins 4 Pole to 5 Pole Trailer Wiring Adapter, part # 47515. Installation is simple and consists of connecting your existing 4-pole and making one single splice connection to the reverse light circuit at the back of the van. You can use a circuit tester such as # PTW2993 to confirm which wire carries the reverse light...
    view full answer...
  • Trailer Lights Turn Off when Headlights are On and Brake Pedal is Pressed
    This sounds like a ground issue or a possible short. Ground problems normally show up when there is more draw on a system such as when you have the running lights on and then use another function like a turn signal or brake light. A short could come from a dirty or corroded trailer connector. Make sure that the vehicle side and trailer side connectors are clean and free of corrosion inside and out. The main connector grounds should be attached to clean and corrosion free bare metal surfaces. The...
    view full answer...
  • Troubleshooting Trailer Brake Lights that Dont Function
    First thing you should do at this point is test the 7-way of the wiring harness with a circuit tester part # PTW2993 for voltage on all of the right pins when the taillight signals are being applied. Just like in the video I attached. If the voltage checks out there but the trailer lights still don't function right then the problem is on the trailer wiring. That would mean that problem is either due to a ground issue or a short issue. Make sure that the trailer side connector are clean...
    view full answer...
  • Recommended Trailer Wiring Harness for 2015 Honda Pilot
    If you currently pull, or see yourself in the future pulling, a trailer with a 7-Way trailer connector, I highly recommend going with the 7-Way Trailer Connector # 118265. It will be much easier to adapt the 7-Way to a 4-Way in order to pull your 4-Way flat trailers that it would be to later purchase the components to pull a 7-Way. If you decide to go with the 7-Way wiring set-up and need an adapter to connect 4-Way flat or 5-Way flat trailer connectors, I recommend using the Hopkins 7-Pole...
    view full answer...
  • Left Side Trailer Stop/Turn Signal Lights Not Working
    If there are no brake/turn signal lights on the left hand side of your trailer then the first thing you will want to do is check the fuse for that circuit in your vehicle's fuse box. It should tell you in the owner's manual where that fuse is located but if not it will be labeled on the underside of the cover/lid. After the fuse is checked you will then need to test the left hand brake/turn signal circuit on the vehicle side trailer connector. If no power is present then there is most likely...
    view full answer...
  • Troubleshooting Wiring Where Only One Side of Boat Trailer Has Lights Working
    I recommend checking the ground connections on the wiring and lights. Most lights have a ground through the mounting hardware of the light, so I recommend making sure the ground is bare metal to metal and free of corrosion and debris. On a boat trailer it is likely there is a main ground on each side at the tail light mounting hardware. If you don't find sanding the metal at each ground and reconnecting it solves your issue then I recommend getting out a circuit tester like # PTW2992...
    view full answer...
  • Parts Needed To Install a 7-Way, 5-Way and 4-Way On a 2000 Oldsmobile Bravada
    You will need the Reese Replacement 7-Way RV-Style Trailer Connector # A10-7072VP on your 2000 Oldsmobile Bravada if you have the factory wiring connector behind your bumper. If your Bravada does not have the factory tow package wiring you will need the Universal Wiring Harness w/ ModuLite and Brake Controller Harness - 7-Way Trailer Connector # 22551. Both of these will give you a 7-way connector which you can then use an Adapter # 37385 when you have a trailer with a 4-way or 5-way flat...
    view full answer...
  • Recommended Components Needed For Flat-Towing 2016 Ram 2500 4x4 Diesel
    I called my contact at Roadmaster and there are no base plates designed to work with your StowMaster tow bar available. The weight capacity of the StowMaster is just too low to use with your truck. In order to flat-tow your Ram 2500, you would need the Roadmaster MS Base Plate Kit, part # RM-296-2. You would then need to upgrade your tow bar to the RoadMaster Blackhawk 2 All Terrain Tow Bar, part # RM-422. This tow bar will work with the base plates I mentioned and it has a 10,000-lb...
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  • How to Determine Trailer Wiring Functions for Installing New 7-Way Connector
    The colors that are used on your trailer are not the industry standard colors so you would need to test them to determine their function when wiring up a new connector for them. One way is to use a jumper wire from a 12 volt battery to put current on each circuit to see what light functions illuminate. Or you can trace each of the wires to see where they go and determine it from there. For a new 7-way to wire to the trailer we have the part # H20046. I attached a chart that details what...
    view full answer...
    Image 1 for
  • Troubleshooting 7-Way on a 2001 Chevy Truck that All Circuits aren't Functioning
    The first place you will want to check is the fuse box on your 2001 Chevy 2500 Silverado. You will want to look for the trailer wiring fuses and replace them as needed. Since I am not entirely sure what circuits on your truck aren't working it could be you are missing a couple connections under the hood of your truck for the brake controller wiring to be completed. Check out the FAQ article I attached to the right for more info on this. Corrosion in the 7-way connector or on the back...
    view full answer...
  • After Installing New Trailer Lights and Wiring, Trailer Lights Will Not Work Properly
    This sounds like a ground problem and possibly a wiring issue. The lights should have something that indicates the wire functions on the back of the housing so it is easy to check those. There should be one wire for the turn signal/brake lights, and one wire for running lights. Then there will be either a separate ground wire or the lights ground through the mounting studs. When there is a weak ground not all functions will work. A weak or bad ground can be caused by corrosion at the grounding...
    view full answer...
  • Adapter to go From Vehicle 7-Way to Trailer 4-Way
    You can attach the 4-way from your trailer to the 7-way on your Ram with an adapter, but there isn't a replacement for the factory 7-way on your '98 Ram 2500 that has a combined 7-way and 4-way. So what you can use is either of the following: - 7-Way to 4-Way Flat Trailer Connector Adapter # HM47365 - Adapter 7-Pole to 4-Pole and 5-Pole # 37385 You can just plug either of these into your truck's 7-way and then connect your trailer's 4-way and you're set.
    view full answer...
  • Trailer Lamps Work Fine Until Vehicle Headlights Are Turned On
    You're having a ground problem, what you describe are the classic symptoms. When the vehicle headlights are switched on, the maximum amperage will be drawn through the system which is when the problems show up. There's a few specific areas you'll want to check. 1) Make sure the trailer connector socket on the tow vehicle is grounded to the vehicle frame or chassis, and that the connection is tightly made to metal that isn't rusty. 2) Make certain that the main trailer ground which...
    view full answer...
  • Troubleshooting a Trailer that Blows Vehicle Tail Light Fuses and Sparks When Touched to Hitch Ball
    It sounds like there is a 12 volt short on your trailer. The spark you are seeing is because your trailer frame has 12 volts running through it and its grounding to the ball and sparking. It sounds like its the running light circuit since that would most likely be the circuit that would be left on if you were hitching or unhitching a trailer. This would also explain why your tail light fuse is blowing. You should go over the running light circuit very carefully and see if there is any...
    view full answer...
  • Troubleshooting Trailer Wiring of 2003 Dodge Ram 2500 Not Functioning
    Sounds like the problem is the wiring on the Ram truck based on what you described. I would inspect the wiring that goes into the connectors at the rear of the truck and look for any obvious signs of damage like cut or exposed wiring and fix as needed. Another really common culprit is corrosion or dirt on the ground pins of the 7-way which sandpaper will easily fix. I also attached a help article on trailer wiring troubleshooting for you to check out as well.
    view full answer...
  • Malfunctioning Turn Signals, Clearance, and Tail Lights on 6 by 12 Foot Trailer
    It sounds like you have an improper ground. This is confirmed when the maximum amperage is on the system (with headlights on), and the lights do not work at all. This indicates a grounding problem. This ground issue could be in a couple of different places; it could be in the vehicle connection plug, a ground wire on the trailer itself, or on one of the trailer lights that require grounding through a mounting location. Since you said you checked your truck connection I would check the...
    view full answer...
  • Troubleshooting a Left Trailer Light Not Functioning
    First I would check the ground of the left tail light assembly. It sounds like the light is not getting a strong enough ground and because of that it is not illuminating. You will want to make sure that it is connected to a clean metal surface. If it grounds through the mounting hardware then you will need to make sure it is mounted to a clean metal surface. Next check the back of your trailer connector on your tow vehicle, look for corrosion or exposed wire that could be causing a short...
    view full answer...


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