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  1. Custom Fit Vehicle Wiring
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  4. Trailer Hitch Wiring
  5. 7 Round - Blade
7-Way Trailer Adapter for Towing Trailers with LED Lights

7-Way Trailer Adapter for Towing Trailers with LED Lights

Item # C57003
Our Price: $27.49
Custom Fit Vehicle Wiring
Orders above $50 qualify for Free Shipping
Shipping Weight: 0.93 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. 1-833-496-1390 to order CURT custom fit vehicle wiring part number C57003 or order online at Free expert support on all CURT products. Guaranteed Lowest Price 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 (80)
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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   (80 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.


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!


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.


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.


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.


The best customer service I have ever seen I have ordered a lot of truck parts from your company and have been treated the way a customer should be treated. Keep up the great customer service. Thanks David


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!!


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.


Furrion camera and my BMW don't get along. Transmission keeps cutting in and out. Thought this adapter might fix it, but was no help.


Did not work on 2017 Land Rover Discovery w/ factory tow-assist. Good support from etrailer.


lights work but not the brakes. Seems to blow a fuse or reset when I plug in my Curt Echo brake controller. Need to figure out a brake controller for my 2014 VW Touareg


After having my 2012 GL450 in the Mercedes shop all day, the head technician called me to discuss the light issue. I mentioned this adaptor. He called back later to say he thought I solved the problem. He felt so bad he only charged me for an hour of labor. Bottom line, I order the part and it was the magic pill. Worked great. Just wish I knew about it for my previous trailer. Ran coast-to-coast over three weeks with the lights on the fritz.


Fits well works well no issues


Functions as advertised


Works fine. My Mercedes GL450 does not recognize the LED lights on my trailer. This fixed the problem.
I've used it approx 20 days over the past year


I purchased this hoping it would power the led running lights and back up camera which are wired to the running lights on my camper hooked to my 2020 GMC Sierra 1500. It works!! There was a lot of head scratching until this adapter was discovered. All my friends trucks powered the LED lights but not the 2020. Big head ache resolved!!


A great product that is a simple solution to GM's problem that they won't admit to


Item worked great. After 3 1/2 years of the dealer trying to figure it out, this did the trick. Back up circuit on the factory wiring for the trailer did not work, although all the other circuits did, even with LEDs on the trailer. Now all of it works. If I could just get rid of the error messages looking for trailer directionals and running lights. I am just using the plug for auxillary back up lights which now work nicely. Adapter is used on Mercedes GL 350.


I have a new 2020 Chevy 3500 and the trailer lights don’t work with led’s. I know one of chevy’s well thought out plans. I took it to the dealership and they told me I’m outta luck and switch my three trailers over. I’m sure you know how that conversation went. I found this online and it works flawlessly so far. Thanks Chevy for your great customer service, NOT.


Great product - but took over a year to receive product


I used this adapter to pair my prodigy brake controller with my 2015 porsche cayenne. Some non-domestic tow vehicles require this step to properly complete the initial pairing of the prodigy to the tow vehicle. Once the initial pairing was completed I could remove this adpater


We found out during pickup of our new trailer that the Mercedes GL is incompatible with trailers with LED lights. Lots of searching on forums appeared to indicate this harness would correct the issue, and it did. Just a note: on eTrailer this harness is shown as incompatible with the Mercedes GL. but that is only because the OEM trailer hitch uses a 4 pin connector. If you have added an electronic brake controller (as we did) the harness was replaced with a 7 pin connector, which is compatible with this harness.


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.
Ed - 05/28/2017


Great price and fast delivery. Great jo b!!


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


Works as advertised and attaches secure ly.

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