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Adapter 7 Pole to 4 Pole with Tester and Cover

Adapter 7 Pole to 4 Pole with Tester and Cover

Item # 47345
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47345 - Single-Function Adapter Hopkins Trailer Wiring
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Great Prices for the best trailer wiring from Hopkins. Adapter 7 Pole to 4 Pole with Tester and Cover part number 47345 can be ordered online at or call 1-800-940-8924 for expert service.
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Hopkins Trailer Wiring - 47345

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

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

Similar to 18142 and 30702

47345 Adapter 7 Pole to 4 Pole with Tester and Cover

California residents: click here

Video of Adapter 7 Pole to 4 Pole with Tester and Cover

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

Video Transcript for Hopkins Adapter 7 Pole to 4 Pole with Tester and Cover Review

Randy: Hey guys. It's Randy here at We get questions all the time from customers asking us how they can get their 7-pole to work with different style connectors. What we're going to look at today is from Hopkins, and this is a 7-pole to 4-pole adapter. This is going to plug right into our 7-pole. It's going to give us the functions we need for a regular 4-pole plug.

Basically what that means is that we can run a 4-pole trailer connector just like this through our 7-pole plug by using this adapter.This is going to eliminate the need for us to modify our vehicle's wiring, add a separate 4-pole onto it. And it's also going to reduce the need for us to replace the plug on our trailer and switch it over to a 7-pole round or something like that. They plug in really nice and easy. There's a couple things that make this one a little bit different than what we're used to out of these adapter. One's going to be the lights that we see here.

This is going to give us signals and indicate to us that our running lights are working. Our left turn and brake are working, and our right turn and brake are working. If we hook up to our trailer, plug it into our truck, and the lights on our trailer aren't working, as long as these lights are working, we know it's not our truck. It eliminates 50% of the possible problem. And we can do the work on our trailer that we need to.Something else that I like that we don't always see on the adapters, some of them have them, some of them don't, but that's going to be a cover.

It's going to go over and protect our connection. Now you could leave this installed on the back of your truck if you don't use your 7-pole. And I recommend taking it out and throwing it in the glove box, something like that. We always recommend using dielectric grease, but if you're going to leave it installed, I highly recommend it.Basically we're going to put that on both sides of our plug. It's going to prevent moisture from getting in.

If we can prevent moisture, we prevent dirt from being built up in there. And if we don't have moisture, we don't have dirt, we're not going to have corrosion. Corrosion on our prongs on both sides can lead to a lot of lighting failures on our trailer. Using a little bit of grease, keeping it on there, it's going to prevent most of that.Now as far as installation, just going to lift up our cover, then we're going to slide in our plug just like that. At that point, we're going to take our 4-pole, plug it in like that. We're going to be ready to head down the road. As you can see, that's a really quick and easy solution to a common problem. Now to show you how the indicator lights or the LED lights on there are going to work, we'll turn on our headlights. You'll see the light come on. We've got our left turn signal, our right turn signal. And then they'll both come on for our brakes.Now I really like this adapter. It's more compact than some of the other ones I see. And I also like that it has the cover and it has the lights. If I was looking for a 4-pole only option, I'd definitely choose that one. If you wanted to upgrade that slightly and have some more adaptability available, I might go with 78118. That's going to be a 7-pole to a 5-pole adapter. That fifth pole can be important if you want to run reverse lights on your trailer. So when you hit reverse in your truck, the lights come on in the trailer. You can see where you're going. Or in a marine application, not really like this, but some of them have a surge coupler here on the front. That surge coupler as it squeezes applies brakes on the trailer. So in that application if you back up without an electric lockout or a manual lockout, the trailer won't go. The brakes will be applied.You can also use that fifth pole for your electric lockout, so when you hit reverse, your trailer will back up. Outside of that, I think this would be an excellent decision. As far as how it's made, how it fits together in the fit and finish, Hopkins has done a really good job on all the seams. There's no gaps. There's no cracks. Really no over mold on the plastic. You can tell they've really taken their time to make a very good product.

Customer Satisfaction Score:

Customer Reviews

Adapter 7 Pole to 4 Pole with Tester and Cover - 47345

Average Customer Rating:  4.9 out of 5 stars   (554 Customer Reviews)


I have ordered several adapters and complete trailer wiring harnesses from Etrailer. All have been top quality. I have saved a lot of money on the plug and play trailer harnesses. Several hundred dollars when they are factory installed, less than $75 from Etrailer.


ETrailer had exactly what I wanted at a fair price. Website was easy to navigate and purchasing was simple. Shipping was fast and I was kept notified right up to when I received my order.


Plugs in easily, shows that pins are producing voltage, and locks in place using the spring loaded door to the 7-pin.


etrailer was great to work with and kept us notified about shipping status. The trailer arrived when promised, went together easily. looks great and we look forward to using it this spring to haul our two kayaks.


Great hitch, perfect fit and quick install on my '17 Nissan Frontier S King Cab.

The Factory Tow package light install is outstanding for a plane-Jane truck like mine. Easy install. My only complaint is that it doesn't come with a mount bracket. I picked one up local, but decided to mount the connector in the steP-bumper for more protection.2" hole saw is perfect, and #10 stainless screws with washers and lock nuts.

Adapter with the test lights is perfect for making sure everything is working.

Great set up, about 1 hour total install time start to finish.


I found this to be the best model due to the l.e.d indicator lights. The other options were the red or blue glowing adapters or none at all. It works perfect and appears to be very well made. Converts a 7 pin plug (1 center 6 in a circle) to a 4 pin plug (three female one male).
Thank you again etrailer for having such a large selection of products and excellent customer service!


Works great.


Worked great, matched up with the trailer light receptacle on my Kia Borrego like a charm. Very pleased.


Well priced, fast shipping, great customer service and adapter works well. Easy transaction. Would highly recommend shopping with etrailer.


Good price


It is versatile, compact, and affordable. Good Job.


Arrived on time and in good condition. Item looks good, have not used it yet.


Quick and inexpensive way to convert a 7 pole to a 4 pole. The built in tester is an added bonus to ensure your wiring is correct.


Good adapter


Glad I purchased this adapter with the tester. It really helps knowing ahead of time that you have power before plugging into your trailer. Highly recommended


Good adapter would buy again


I used this wiring kit with the Honda hitch. I would recommend installing the 7-way receptacle to the mounting bracket on the hitch prior to installing the hitch to the car. You will need to drill holes in the mounting bracket on the hitch since the ones on the receptacle don't line-up with the ones on the bracket. I used four stainless steel screws and nuts with nylon inserts to connect everything together. The rest of the installation went just like the video, easy.


This was just what I needed for my new used pickup to hook up my trailer.



If this tells you anything, somebody stole the first one I bought, so I bought another one. This 7-way to 4-way adapter is just what I need.


Thank you for the fast shipping and quality products. Worked Perfectly.


The review was two stars, and the comments were that the LED lights do not work with my vehicle as the device is apparently not compatible with a 2017 Mercedes GLS. I believe before the vehicle will energize the turn signal, brake, or flasher circuits, the Mercedes needs to sense more resistance as would come from incandescent trailer light bulbs . Recommend that the manufacturer put in resistance in parallel with the LEDs to simulate the load of incandescent bulbs.

Etrailer Expert

Heather A.


Thank you for your review. This particular adapter does have a hard time sensing the load of LED lights because they draw such little power. I recommend 7-Way to 5-Way4-Way Trailer Adapter for Vehicles with Lamp-Out Sensors part C35FR which is designed specifically for Audi, Mercedes-Benz, Porshe, and Volkswagen vehicles with the factory tow package.


The adaptor fit well and seemed to work well until the right trailer turn signal didn't work. I replaced the bulb and still didn't work (would not indicate). The lights would turn on and indicate when braking but the right turn signal would not work and the left one flashed both lights like hazards. When I put on my wife's car (doesn't need the adaptor) it worked fine so the only thing that could be the problem is the adaptor or my car.

Etrailer Expert

Mike L.


You made a great start in the troubleshooting process by trying the trailer with another vehicle. Now, you will need to determine if the problem is with the wiring on the vehicle or with the adapter. You will need an incandescent circuit tester like the # PTW2993 we offer. Plug the adapter into the 7-way on the vehicle. Use the tester on each pin of the adapter as the indicator and brake lamp functions are activated. If everything tests okay at this point, you might have a slight ground problem on your trailer. Some vehicles are more sensitive about ground problems that others, so its entirely possible that a slight ground problem on the trailer would cause problems on your vehicle, but not when you tried it on another. If you do not get the correct signals on the adapter, unplug the adapter and test the 7-way on your vehicle. If the connector on the vehicle works okay, then the adapter is bad and should be replaced. If the 7-way is not working correctly, check the vehicle fuses that protect the towing circuits. The location of these should be shown in the owners manual. I will link you to an article that explains more strategies on troubleshooting trailer wiring.


Received the adapter today. Plugged it in to check function. Works well. Very Pleased with purchase. Thank you.


This connector is perfect when you already have just the 7 way on your truck. I HIGHLY RECOMMEND this connector, it's a great way to go if you don't want to install a connector that has both. Buy it you won't be sorry!!!!

Larry W.


It is a great tester


There are so many options available - Etrailer detailed description makes it easy finding exactly what you need.
Great product for the price.



Quality Product: Working great despite being abused by this nasty weather. Connections holding up well.


These wiring components work perfectly. They were easy to install with the instructions. Anybody can do this. I got the 7-pole connector in this package and also bought a 7-pole to 4-pole adapter with a test light so I could make sure that the connections were working. I also bought the Polak PK12711Y bracket to put on my trailer hitch. I tried the standard bracket from Walmart but they did not match the hole pattern on the 7-pole connector. Carol C recommended the Polak bracket and the hole pattern matched perfectly. I can now pull my trailer. I will return to etrailer for any of my trailer or other vehicle part needs. Thanks you etrailer.

Show More Reviews

See what our Experts say about this Hopkins Trailer Wiring

  • What do I need to Convert a 4-Way to 7-Way Trailer Connector on a 2005 Lincoln Navigator
    You would use 4-way to 7-way adapter, part # 30717. You would extend the yellow lead on the adapter and tap it into the reverse light circuit on your Navigator. The easiest way to access this circuit is from behind the taillight assembly. White will need to be connected to to the Navigator frame for ground. Since you have surge brakes, the blue wire is not need and can be taped up. The black wire is for providing a 12V power feed from the vehicle to a battery or electrical system on the...
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  • Recommended 7-Way to 4-Way Adapter for 2012 Mercedes-Benz GL450
    For a 7-way to 4-way adapter I recommend the Pollak 7 Pole to 4 Way Connector Adapter # PK12716. This adapter will plug into the 7-way connection at the back of your vehicle and allow you to then plug in the 4-way from your trailer to power your trailer's signal lights. I have attached a video review for your reference.
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  • Adding a 7-Way Trailer Connector and Brake Controller to a 2008 Nissan Pathfinder
    In order to add a 7-Way trailer connector to your 2008 Nissan Pathfinder you will need a 4 and 7 Way Installation Kit, # ETBC7. This will provide a 7-Way trailer connector at the back of the vehicle and all of the wiring to install a brake controller. A brake controller is needed in order to activate the trailer brakes. For a brake controller, I recommend the Tekonsha Prodigy P2, # 90885. It is one of our most popular models because it is easy to set up and easy to use. I have included...
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  • What are the Functions of the Black and Purple Wires Hopkins Plug-In Simple # 47185
    The black wire is the 12 volt power source that you could use to help maintain the charge of a battery or for any other 12 volt accessory. I would recommend that you use 10 Gauge Blue Primary Wire, part # 10-1-1, through a 40 amp. In-Line Circuit Breaker, part # 9510, to your 2003 Dodge Ram Van battery. The purple wire will have power when your tow vehicle is in reverse. Typically this circuit is used trailer backup lights, or a reverse lockout solenoid on a trailer with surge brakes. I...
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  • Tow Bar Wiring Recommendation for a 2014 Ford F-150
    We have exactly what you will need. First you will want the Hopkins Tow Bar Wiring part # HM56000. This will plug in line with your trucks taillights circuits to control them while being flat towed. This harness has a 4-way connector that can easily be converted to a 7-way with a # 47345. You will just need to plug the adapter into the 7-way socket on your tow vehicle and then plug the # HM56000 into it.
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  • Recommended 7-way Connector For 2015 Ford Explorer Without Towing Package
    I would be happy to recommend a 7-way connector for your 2015 Ford Explorer Limited 4WD/AWD. I recommend the Curt T-Connector Vehicle Wiring Harness with 7-Way Trailer Connector # C56306 which will plug into the factory connectors of your Explorer even though you do not have the towing package, and will give you a 7-way connector. To mount the connector to the etrailer Trailer Hitch Receiver # e98867 you will need the no drill mounting bracket # 18140, and mounting bracket # C67UR. When...
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  • How to Wire New 7-way on 2007 Chevy Silverado
    If somebody cut off the 7-way, you can wire in a new one using part # HM40975-11998. The pigtail used by this connector would wire to the factory wiring harness under the vehicle by connecting the red pigtail wire to the yellow wire that carries the left turn/brake signal on the factory harness . The white wire on the pigtail would connect to the white wire in the harness, the blue wire on the harness would connect to the blue wire on the pigtail that carries the output voltage from the...
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  • Replacement 7-way for 2009 Audi Q7 and 7-way to 4-way Adapter for Trailer with LED Lights
    You are right on both counts! The correct replacement 7-way for your 2009 Audi Q7 is in fact the Mighty Cord Replacement 7-Way RV-Style Trailer Connector for Factory Tow Package # A10-7072VP. In regards to the 7-way to 4-way adapter # 47345, there is a specific one you will want to use if your trailer has LED lights, which is the 7-Way to 5-Way/4-Way Trailer Adapter for Vehicles with Lamp-Out Sensors Towing Trailers with LEDs # C35FR.
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  • Troubleshooting 7-way Connector On 2007 Lexus GX 470 Not Having Power To Running Lights Of Trailer
    Since your 2007 Lexus GX 470 has the factory 7-way connector then it does indeed seem that there is a blown/missing fuse causing the issue. Fuse 8 in the engine bay fuse box is the fuse for the lights, so I recommend making sure that the fuse is not blown or missing. If the fuse checks out, then use a circuit tester like # PTW2993 to test the 3 o'clock pin on your 7-way connector and see if there is power on the pin. While you are there go ahead and check that there is no corrosion or...
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  • How To Add 4-Way To Truck With 7-Way Trailer Connector
    The easiest option to tow a trailer with 4-way when you have a 7-way would be an adapter, the Adapter 7 Pole to 4 Pole part # 47345. If you need to use both or would just like to have both accessible at the same time then you can swap out the existing 7-way with a 4 and 7-way, the 7-Pole and 4-Pole Trailer Connector Socket part # HM40975-11998 or just the 7- and 4-Pole Trailer Connector Socket part # HM40975.
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  • Can 7-Way to 4-Way Adapter # 47345 be Used with Light Up Hitch Cover
    Yes, the hitch cover you mentioned does use a 4-way to illuminate it so the 7-way to 4-way adapter part # 47345 would be the correct adapter to use.
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  • How to Plug the LED Light Kit into a 7-Way
    You are correct that for the Curt Cargo Carrier, part # C18151, the compatible LED Light Kit, part # 98174LED, and the License Plate and Tail Light Mounting Brackets, part # e98943-44. The Light Kit uses a 4-way to connect to your vehicle's electrical system. To use this with your 7-way, you will need an adapter. I recommend the Adapter 7 Pole to 4 Pole with Tester and Cover, part # 47345. It will plug into your 7-way and allows you to plug the Light Kit's 4-way in. I've...
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  • Trailer Connector Adapter for a 1994 Ford F-250 to Tow a Boat Trailer with a 4-Way Connector
    The easiest way to tow your boat that has a 4-way trailer connector using your 1994 Ford F-250 with a 6-way connector is to use an adapter like # 47305B. If you have the more common 7-way blade connector on your truck you can use # 47345. Either simply plug into the truck's connector then you connect the trailer's 4-way. Since they're small they can easily be stored when not in use. The best part is whichever one you need will make you legal.
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  • Recommended Adapter For 7-Way To 4-Way Flat Connector
    On your 2004 GMC Sierra, I recommend an adapter like the Hopkins Adapter 7 Pole to 4 Pole with Tester and Cover # 47345. This will convert your 7-way vehicle side connector into the 4-way flat for your trailer.
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  • Would the Adapter 7 Pole to 4 Pole 47345 Fit a 2004 Chevy Silverado
    If your 2004 Chevy Silverado has a 7-way connector on it like the part # PK11893 yes, the part # 47345 would fit it and work well.
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  • Installing 7-Way Trailer Wiring for a Gooseneck Trailer in the Bed of a 1999 Chevy Silverado
    You could use the 7-Way Pre-Wired Car Connector, # 20023, and hardwire it by function into the existing 4-flat wiring. You will need a circuit tester like # ALL640595 to find the wire functions. If your 1999 Chevy Silverado has the round plug with a cap above the spare tire, you can use Replacement Multi-Tow 7-Way and 4-Way Trailer Connectors, # 30955. This connector will plug into the factory connector. You could then route the harness up inside the side of the bed and drill a hole to...
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  • Flat Tow Wiring for a 2008 Jeep Wrangler Unlimited
    From the little bit that I could tell from the Cool Tech website, it looks as though their wiring harness works the same as the Hopkins Kit that we offer. The big difference is that the Hopkins Kit already has the 4 pole harness installed whereas the Cool Tech version you would have to attach the 4 pole wiring harness so that you can connect your wiring to an adapter for your RV. The Hopkins Custom Tail Light Wiring Kit # HM56200 that you referenced plugs into your Jeep's tail lights without...
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  • 4-Way Adapter Recommendation for a 2004 Jeep Wrangler
    A square 7-way is not a standard style of trailer connector. It could be possible that you have a round, blade-style 7-way and then all you would need to convert it to a 4-way would be a # 47345. Or you could just install a new 4-way with the part # 118409 and bypass the 7-way all together.
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  • Can Trailer Battery be Charged Using Adapter 7 Pole to 4 Pole with Tester and Cover # 47345
    Since Adapter 7 Pole to 4 Pole with Tester and Cover Item # 47345 has a 4-Way on the side the trailer plugs into it only has the light functions. All 7- to 4-Way adapters are like this. But what you can do is wire the trailer battery to the running light circuit on the trailer. Then, if you have the headlights on, it will provide a maintenance charge to the battery.
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  • How Does OEM Tow Package Wiring Install to a 2009 Honda Pilot and What Adapters are Need for 4-Way
    Since your 2009 Honda Pilot has the tow package it will have a port or plug for this harness to plug into. There are 4 holes in the 7-Way connector so that you can mount it to the bumper. Some vehicles have knockouts in place that can be removed and provide a pre-drilled location for the 7-Way. Take a look at your bumper to see if a knock out is there. If there is no knock out, you can attach to the bumper using a bracket like part # 18138. There may also be a 4-Way already in place tucked...
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  • Trailer Connector Adapter for e98943-44LED Cargo Carrier Light Kit on 2015 Honda Pilot
    The # e98943-44LED etrailer brand License Plate and LED Taillight Mounting Kit uses a standard 4 pole trailer connector plug, which would be compatible with a standard 4 pole trailer wiring harness like what would be provided by # 118558. If your Pilot has a 7-way trailer connector, you'd simply use an adapter like # 47345. I've linked to an install/demonstration video for the light kit as well as to a video for the adapter I recommended.
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  • What Do Each of the Lights on Adapter 7 Pole to 4 Pole with Tester and Cover # 47345 Indicate
    The test lights on the 7 to 4-Way Adapter # 47345 will illuminate when there is a signal showing that the circuits are working (on the vehicle side). The bottom one will light up when the running lights are working. The center light will illuminate when the left turn signal and brake lights are working. And the top light will illuminate when the right turn and brake lights are working.
    view full answer...
  • What is the Diameter of Adapter 7 Pole to 4 Pole with Tester and Cover, # 47345
    I went out to the warehouse and measured an Adapter 7 Pole to 4 Pole with Tester and Cover, # 47345. It has a diameter of 1-5/8 inches. With that said, it is designed to fit in a standard RV-style 7-Way trailer connector. So if your vehicle has a 7-Way, chances are it is an industry standard size and it should fit. If the connector on your vehicle is a different size then you could replace it with Hopkins Endurance Multi-Tow 7-, 5- and 4-Way Flat Trailer Connector, # HM48470, and you would...
    view full answer...
  • Recommended 7-Way To 4-Way Adapter For 2014 Mercedes-Benz ML350
    For your 2014 Mercedes-Benz ML350, to adapt from your 7-way on your vehicle to a 4-way trailer connection for your Malone MicroSport trailer, I recommend the Hopkins Adapter 7 Pole to 4 Pole with Tester and Cover, # 47345. This will give you the ability to connect your trailer but also to test your functions at the connection point for easier troubleshooting. If you want the 4-way with options of a 5-way and 12V power socket, I recommend the Hopkins Multi-Tow Trailer Connector Adapter...
    view full answer...

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Employee Alexander C
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