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Reese Trailer Connector Adapter w/ LED Circuit Tester and Dust Cover - 7-Pole to 4-Pole or 5-Pole
Reese

Reese Trailer Connector Adapter w/ LED Circuit Tester and Dust Cover - 7-Pole to 4-Pole or 5-Pole

Part Number: 78118
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$24.61
Retail:$31.30
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Custom Fit Vehicle Wiring
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This adapter lets you quickly convert your 7-way connector for use with a 4-way or 5-way flat trailer-end plug. It includes a circuit tester with red LEDs and a built-in dust cover that protects the terminals when you aren't towing. 1-800-940-8924 to order Reese custom fit vehicle wiring part number 78118 or order online at etrailer.com. Free expert support on all Reese products. Great prices and Fastest Shipping for Reese Trailer Connector Adapter w/ LED Circuit Tester and Dust Cover - 7-Pole to 4-Pole or 5-Pole. Custom Fit Vehicle Wiring reviews from real customers.
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  • Reviews (84)
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Reese Custom Fit Vehicle Wiring - 78118

Highlights

  • Multi-function adapter: Converts 7-Way to 4-Flat or 5-Flat connectors easily.
  • Built-in LED Tester: Red LEDs make checking electrical circuits straightforward.
  • Dust Cover Included: Protects from dust and grime when not in use.
  • Durable plastic design: Ensures longevity and reliable connection.
  • Versatile usage: Supports both vehicle and trailer troubleshooting.
  • Easy to use: Ideal for vehicles with RV-style, 7-blade connectors.

Features to know about

Check Electrical Circuits Instantly: LED Circuit Tester

No more guessing games when it comes to your trailer lights! The Reese Trailer Connector Adapter is equipped with a built-in LED circuit tester featuring highly visible red LEDs. These lights indicate power to your running, turn, and brake light circuits at a glance, making it incredibly easy to diagnose any electrical issues right on the spot. Perfect for the avid DIYer, these indicators save you time and effort by instantly telling you where the problem lies.

Dust? Not a Problem: Built-in Dust Cover

Protecting your trailer connector from dust and grime is a breeze with the Reese Trailer Connector Adapter's built-in dust cover. When you're not towing, this handy feature ensures your terminals stay clean and ready for the next adventure. It’s an essential for keeping your connector in pristine condition, even when you're not using it, ensuring reliability every time you hitch up.

Universal Compatibility: Converts 7-Pole to 4 or 5-Pole

Whether you're towing a trailer with a 4-way or 5-way flat connector, this adapter has got you covered. Simply plug it into your vehicle's 7-blade round connector, and you're ready to connect trailers with either flat configuration. Versatile and easy to use, it’s a must-have for anyone who needs a quick and reliable conversion solution on the go.

Perfect Fit for Multiple Vehicles: Works with Trucks, SUVs, and More

Own multiple vehicles with different towing setups? The Reese Trailer Connector Adapter is incredibly versatile, accommodating 4-wire or 5-wire flat, trailer-end connectors. It’s the perfect companion for a variety of towing scenarios, making it ideal for use with trucks, SUVs, and more. Whether you’re hauling a boat, camper, or utility trailer, this adapter ensures a seamless transition from vehicle to vehicle.

Easy Troubleshooting: Multi-Function Adapter

If troubleshooting is on your mind, this multi-function adapter is the ideal tool for making detailed checks on your vehicle and trailer circuits. Thanks to its LED indicators, it takes the guesswork out of determining if the fault lies with your vehicle or the trailer itself. For those who prefer a proactive approach to trailer maintenance, this adapter is the perfect diagnostic assistant.

Store with Confidence: Lightweight and Compact Design

There's no need to worry about storage space when you're equipped with the Reese Trailer Connector Adapter. Its lightweight and compact design means you can easily stow it away when not in use. Keep it in your glove box or tool bag so you're always prepared when the need to tow arises.

78118 Reese Trailer Connector Adapter w/ LED Circuit Tester and Dust Cover - 7-Blade to 4-Pole or 5-Pole




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Video of Reese Trailer Connector Adapter w/ LED Circuit Tester and Dust Cover - 7-Pole to 4-Pole or 5-Pole

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




Video Transcript for Reese Trailer Connector Adapter w/ LED Circuit Tester and Dust Cover Feature Review

Hey guys, it's Randy here at etrailer.com. Now a common question that we get here is how do I adapt my seven pole on my vehicle to work with a trailer that has maybe a different connector on it As you can see here we're going to take a look at the Reese Towpower adapter. Now this adapter is going to take care of a lot of different things for it. I really liked the way this deal works. Basically this is going to plug into your seven pole. It's going to give us a working five pole, a working four pole, but also if you can see those little red LEDs in there.

This is going to diagnose a trailer connection problem that we might have. So with this plugged into our vehicle, we'll turn on our headlights, make sure that the tail light bulb comes on, left blinker, verify that. Right blinker, verify that.Then hit her brakes and make sure they both come on. This is going to ensure that we don't have any problems with our vehicle, so we're going to know from that point the issue we're looking for is in our trailer. It eliminates half the equation just by plugging it in.

I think that is really neat. Now where this one differs from a lot of the other seven to four and five adapters that we offered, that his one actually has a four pole slot and the five pole slot. The five pole slot is going to give us our ground running lights, our left turn and brake, our right turn and brake, and our reverse signal.Now that fifth pole is for our reverse signal. We're going to use that reverse signal most of the time in a marine trailer application that has an electric lockout for its surge brake. As you back up, you put pressure on that.

That can apply the brakes in the trailer. It's kind of a situation if you can't back your trailer up. So by sending that circuit to that lockout, that fluid isn't transferred, we can easily back up. A lot of customers also ask if you can run backup lights on your trailer off of that circuit, and you absolutely can mount a couple of lights back there. When you hit reverse they're going to come on.

They'll illuminate the ground behind you.Now on the four pole side it's going to have all of those same signals with the exception of the reverse. Now most adapters like this are just going to have the five pole, your left to stick the four pole in. The reason I like this being this way, with the shrouded four pole connector it's going to have a black shroud that goes all the way around here where these are kind of down inside it comes up to about here. If you're trying to connect that onto a five pole, that shroud gets in the way right there and it won't allow you to connect it properly. So this completely eliminates that issue. Any four pole, it's going to sit right in there. You'll see the accommodation going around the outside here for that sleeve to fit into. I think they really thought this out really well to ensure that we're going to have good long lasting life out of this for one, but also that it's going to work in the application where we need it.You can also see it's got a dust cover here. We don't see that on all the other ones that are out there. That's going to sit down and over whichever one we're not using. So if we're using our four pole side, we'll cover our five pole side. If we're using our five pole side, we can cover our four pole side, so this is gonna work out in all weather conditions. You'll see that in the reviews. Customer say regardless of the weather, regardless of the situation, this thing works out really well. The installation's going to be just like a regular seven pole. Lifting up our cover here you can see the tab on top. That needs to go behind the tab on our door, place it in. Wiggle that into place. Let that come down and capture it. Then it's just a matter of getting our four pole plugged in there. At that point, just check our lights really quickly, but you'll be ready to head down the road knowing that you've got the signals you need heading out where you need them.Now, let's take a quick look at the diagnostic function and see if we can turn on those headlights. It's going to show us that those are in fact coming on. And we can check our left blinker, our right blinker, and our brakes. That's going to help us ensure that everything on our truck sides working, so we should look at our trailer if we're having any problems. Now there's several other options out there as far as adapters go. I really like the way this one's built. They put a lot of thought into it and I like that it has the tester included. In other situations if you need something with an extension, those are out there and available to give you a little bit more of links on your plug. But all in all, I think it's a really nicely made product. It seems like they put a lot of consideration into how it's going to be used and it's one I would definitely own if I had the need.

Customer Satisfaction Score:

Ratings & Reviews

4.9

84 reviews
This adapter lets you quickly convert your 7-way connector for use with a 4-way or 5-way flat trailer-end plug. It includes a circuit tester with red LEDs and a built-in dust cover that protects the terminals when you aren't towing.

by:

Does what it is advertised



by:

Works as advertised. Etrailer service and prices excellent.



by:

Use it to check my motorhome 7 pole operation and plan to use the 4 pole connector for my curt auxillary LED light that I will attach to my bike rack when its on the motorhome and SUV. Recently used the 4 pole to power car dolly light system on a 900 mile trip. No issues.

Javi profile picture

Javi

3/10/2022

Still works. Rarely used in the past year.



by:

Works well and makes checking the circuit easy. Helps determine if a problem is on the vehicle side or the trailer



by:

Works great for the basic checking of turn, brake and running lights. Overall fit and design is great.

David profile picture

David

3/14/2020

Excellent adapter makes checking the harness easy.



by:

My first experience with etrailer. It was a pleasure. Great products at reasonable prices, with fast shipping.
This adapter performs as advertised. It is a very convenient way to test your vehicles wiring, without having your trailer hooked up.
If I were to be really picky, I would have liked it to have a tighter fit in the vehicle's socket. I'm sure it will be fine though.
I would definitely recommend etrailer!



by:

Item worked as stated fit good and stayed in place. shipping is fast and easy, item came a day early. Etrailer has great pricing an a great selection.

Frank D. profile picture

Frank D.

8/31/2016

Product works as it did on day 1. Holds up in all types of weather. Hats off to Etrailer for a product that works as advertised



by:

I find this product very useful when determining where my trailer light problems are. Having the LEDs built into the plug is a great idea.



by:

Just what I needed for the two trailers I have, one with 4 pins and one with 5. Nice dust cover for the one not in use as well.



by:

I received my trailer wiring harness today and I was so impressed! The details and video of what I was ordering, made the process easy. Even though it said when I would receive it, I figured that during this Christmas time, it would take longer than projected. It came on time!
Thank you!!
Augusta Georgia



by:

Fits perfectly and seems to work although I haven’t actually hooked the trailer wiring to it yet. But the leds light as expected.



by:

Product works as advertised. LED lights work great to check for faults in trailer or vehicle circuits.



by:

I bought a cheaper one at an auto parts store and had issues with it not connecting consistently. This one works great!



by:

Seems well made. Needed for my 2015 Chevy Surburban since it only has 7 way plug and I needed 4 way also. The test lights should come in handy in the future.



by:

Great adapter with the tattle tale LEDs to indicate what lights are energized for trouble shooting circuit problems.



by:

Every time I purchase something from ETrailer it makes me grateful I found this company. Quality product, fair prices, fantastic customer service.
Thank You Odelia!



by:

Thank you for your support. The order arrived as you reported.



by:

Exactly what we needed for our new 2020 Honda Pilot with the towing package. Shipment was prompt too!



by:

Worked just as described. Very convenient plug. All good.



by:

Seems to be as advertised. The dust cover is only on the 5 pole connector.



by:

Well built outstanding adapter. Indicator lights make quick check of lighting systems.



by:

Great product , well designed for my boy trailer , 25 Foot Rosborough .



by:

Received it very quickly. Still need to try it on my boat hitch that is in storage! Praying it works!



by:

Does the trick, converts my 7 Pin to 5 pin.



by:

Works great, good value, looks like it will hold up well

Mike M. profile picture

Mike M.

10/15/2015

Working as it should


25
84
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  • Troubleshooting 2 Lights Blinking on the Reese Trailer Connector Adapter # 78118
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Info for this part was:

Employee Mike L
Expert Research:
Mike L
Employee Michael H
Expert Research:
Michael H
Employee Jameson C
Expert Research:
Jameson C
Employee Tyler C
Written by:
Tyler C
Employee Jacob T
Video Edited:
Jacob T
Employee Adele M
Updated by:
Adele M
Employee Laura H
Updated by:
Laura H
Employee Wilson B
Updated by:
Wilson B
Employee Alexander C
Updated by:
Alexander C
Employee Randy B
Installed by:
Randy B
Employee Zach D
Video by:
Zach D

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