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7-Way Trailer Adapter for Towing Trailers with LED Lights

7-Way Trailer Adapter for Towing Trailers with LED Lights

Item # C57003
Our Price: $29.30
You Save: 43%
Custom Fit Vehicle Wiring
Shipping Weight: 0.91 lbs
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Plug this adapter into your existing 7-way when towing a trailer equipped with LED lights so that your vehicle's computer will recognize the trailer's signals. Designed for use on vehicles with Trailer Lamp-Out sensors. 1-800-940-8924 to order CURT custom fit vehicle wiring part number C57003 or order online at Free expert support on all CURT products. Great prices and Fastest Shipping for 7-Way Trailer Adapter for Towing Trailers with LED Lights. Custom Fit Vehicle Wiring reviews from real customers.
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  • Reviews (107)
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  • Videos (1)
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CURT Custom Fit Vehicle Wiring - C57003

  • Custom Fit
  • Trailer Hitch Wiring
  • 7 Round - Blade
  • CURT

Plug this adapter into your existing 7-way when towing a trailer equipped with LED lights so that your vehicle's computer will recognize the trailer's signals. Designed for use on vehicles with Trailer Lamp-Out sensors.


  • Plugs into an existing 7-way socket to provide a new 7-way socket that is able to recognize LED trailer lights
    • Built-in resistors enable LED signals from your trailer to be read by your vehicle's computer
    • No cutting or splicing required
  • Great for use on vehicles with Trailer Lamp-Out sensors, such as Audi, Mercedes-Benz, and Volkswagen vehicles with the factory tow package
  • Spring-loaded dust cover protects terminals from moisture and debris when connector is not in use
  • 1-Year limited warranty

57003 Curt 7 Way LED Trailer Light Adapter

California residents: click here

Video of 7-Way Trailer Adapter for Towing Trailers with LED Lights

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

Video Transcript for Review of Curt 7-Way LED Trailer Light Adapter - C57003

Jeff Hello everybody, this is Jeff at Today we're gonna take a look at this CURT seven-way trailer adapter for towing trailers with LED lights. Now, this'll basically plug into your existing seven-way socket, and it provides a new seven-way socket that's able to recognize LED trailer lights. They use built-in resistors, which'll enable the LED signals from your trailer to be read by your vehicle's computer. And to install this, there's no cutting or splicing required. It's basically just a plug-in.

This is great for use on the vehicles with the trailer lamp out sensors, like the Audi, the Mercedes and the Volkswagen vehicles that have the factory tow package. What this adapter will do is simulate the increased power draw so the vehicle thinks there's incandescent lights on the trailer. Then you won't get the lamp bulb out reading that usually flashes on the dash of those vehicles. You can see it also, right here, has a nice spring-loaded dust cover. This'll help protect the terminals from moisture and debris when the connector is not in use.

Overall length on this from one end to the other is about 12 inches, and you can see it is a flexible cable. But that should do it for the review on this CURT seven-way trailer adapter for towing trailers with LED lights..

Customer Satisfaction Score:

Customer Reviews

7-Way Trailer Adapter for Towing Trailers with LED Lights - C57003

Average Customer Rating:  4.6 out of 5 stars   (107 Customer Reviews)

Plug this adapter into your existing 7-way when towing a trailer equipped with LED lights so that your vehicle's computer will recognize the trailer's signals. Designed for use on vehicles with Trailer Lamp-Out sensors.


I tried it on a 2007 Land Rover and the trailer lights still pulsed. Didn't work.

Etrailer Expert

Heather A.


Hi Harlan. It sounds like you may have a bad ground. You probably already know this but this adapter is designed to help the complex computer system of luxury vehicles recognize the LED lights on your trailer. Since LED lights draw such a small amount of power, the vehicle's 7-way will not recognize the LEDs on the trailer and that leads to the pulsing. Since you are using the adapter and the lights are still pulsing I recommend to check your ground connections. 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. I am certain this will fix your pulsing issue and if it doesn't, please let me know so we can continue troubleshooting. The light grounds should also be attached to clean and corrosion free bare metal surfaces. If there is anything between a light ground and the metal trailer frame or if the trailer has an aluminum frame, tilt bed, or folding tongue, any of these things can interrupt the ground. Running jumper wires from the light grounds to the main trailer connector ground can help.


Once I figured out what was wrong with my truck, this device is doing exactly what I need it to do. Even without plugging a trailer in, the device gets my truck to think there's a trailer. I purchased a camper that needs the 12v charge and this seems to be the easiest way to get the truck to activate that charge lead.


In October 2021, I purchased several packs of LED bulbs from etrailer and replaced the dim OEM incandescent marker lights and turn signal lights on my 2021 Coachmen Freedom Express UltraLite 192RBS travel trailer.

Replacing the bulbs was a piece of cake and took only a few minutes. When all the bulbs were changed out, I hooked up my 2020 Ford F-150 and connected the 7-wire connector. All of the new LED bulbs worked flawlessly as expected.

When I made my next trip in the travel trailer, I starting getting “fault” messages on my Ford F-150’s instrument cluster. These messages were alerting me to a problem with either the turn signals or the trailer lights. The first couple of times this happened, I immediately pulled over and checked all my lights. Everything was good. I hit the “OK” button on my steering wheel and turned off the warning. During my six-hour trip, I received these warning messages numerous times (and never a problem was detected).

I sent etrailer a note a couple of weeks ago asking if they had encountered this problem before. Becky B. quickly let me know that my problem was not unique. She suggested etrailers Curt adapter (item C57003) as a possible solution.

I quickly ordered this adapter, and I used it this past weekend (26 March 2022). The adapter worked great! No more “fault” messages.

Thank you, Becky B., and etrailer!


Resolved issue with truck not picking up signal from horse trailer


I bought this to tow a little trailer with a 4 pin behind my Tesla which has only the 7 pin. Works wonderfully! No issues at all


A new boat trailer and a couple year old Silverado we’re unable to recognize a light signal. My dealer was no help. The trailer adapter solved the problem and everything works! Quality appears to be very good as well.


I have a 2019 GMC, that I paid 50k for, used. But, it will not recognized my boat trailer. It's a common problem I found out after I bought the truck. The fix is to take it to the dealer for a day or two. Plus dealing with the hassle, OR buy this part, and go on with your life. Life saver !!


As advertised. Great job by etrailer folks with order updates. Received, shipped, and tracking info. I will definitely use etrailer in the future!


I used this adapter on my 2021 Ford F150 to fix a turn signal fault message that kept flashing on screen when I towed my trailers. The pickup computer didn't recognize the LED lights on my trailer.

Works perfectly.

Excellent customer service and fast shipping.


Product was as described and was delivered quickly.


Fixed the issue with my 2009 GL-550.
super bummed when I purchased a new 2018 Flacon 23RB and the trailer dealership couldn't get the lights to work with my GL, even after putting in resisters and couldn't leave the lot with the trailer on the back of the GL, had to a friend's truck. Mercedes didnt have any answers either. So hit Google and found this pig-tail.
Thank you SO much!!


I have been using this adaptor for a year now. The adaptor is very simple to use and works fantastic! Thanks!


Disappointed with the customer service. Wanted to return this item as it did not solve the problem I was having (F150 displaying lighting errors). It was plugged in for a few minutes to test lights but is apparently considered ‘used’ and unreturnable so now I’m stuck with a product I have no use for. Will not be using this company for future orders.


Good price, fast delivery fixed the problem. Can't ask for more then that!

David M.


Great, an easy solution to a difficult problem.


Received on time and works as expected. Will use etrailer again.


Perfect problem solver for LED lighted trailers. I fix mounted adapter, it comes with mounting bracket. I ordered a large rubber cap to cover the plug end to vehicle when not in use. Basically you need to unplug the adapter when not I use or the vehicle thinks a trailer is still attached.


my problem: '11 ML350. trailer LED running lights would only flash (like emergency flashers). All other functions worked find - turn signals, brakes, etc. There were no warning lights/codes, etc displayed on the dash.

This product completely solves this problem - it's a quality built product at a reasonable price. Although the trailer end of the pigtail includes mounting bracket for a permanent installation, I won't go to that extent as I rarely use the trailer. I will most likely just zip tie the pigtail to what ever is convenient to eliminate any flopping around while on the road.



1 yr later - still working great wno issues whatsoever.


I bought this hoping it would fix my 2021 Ford F-150 infamous trailer disconnect from my LED lights on my Echo UTV trailer. It didn’t. Ford recently did an update addressing a trailer brake disconnect error but this did not help the trailer disconnect error happening randomly all the time during road trips. Super annoying to hear the binging all the time.


Works as advertised and attaches secure ly.



Still fits securely. I have noticed that the brakes lights will flash once or twice upon install, but it’s works as advertised.


Timely delivery and good follow up from etrailer. Parts fit and work as expected


Product looks well built, I will find out next week if it works as good as it looks


If you’re using LED lights plugged into your Mercedes Benz 7 pin plug and your vehicle is prior to 2019, Buy this! I was sure I had a wiring problem all along. Just needed the resisters to make the module recognize a trailer.


Strait forward and like described in your sales link.


Fixed the problem with my 2022 FR Sunseeker MBS. No toad lights before, but work now.


Solved the problem that occurred when the led lights of a new trailer functioned improperly apparently because of something to do with a new gmc truck.

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