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Curt Custom Wiring Adapter for Trailer Brake Controllers - Dual Plug In

Curt Custom Wiring Adapter for Trailer Brake Controllers - Dual Plug In

Item # C51522
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Install your Curt electric trailer brake controller quickly and easily with this custom wiring adapter. Simply plug one end of the adapter into your brake controller and then plug the other end into the built-in port beneath your vehicle's dash. Call 800-298-1624 to order Curt accessories and parts part number C51522 or order online at etrailer.com. Free expert support on all Curt products. Guaranteed Lowest Price and Fastest Shipping for Curt Custom Wiring Adapter for Trailer Brake Controllers - Dual Plug In. Accessories and Parts reviews from real customers.
  • All Info
  • Reviews (6)
  • Q & A (8)
  • Photos
  • Why etrailer?

Curt Accessories and Parts - C51522

  • Trailer Brake Controller
  • Wiring Adapter
  • Plugs into Brake Controller
  • Curt
  • Vehicle Specific

Install your Curt electric trailer brake controller quickly and easily with this custom wiring adapter. Simply plug one end of the adapter into your brake controller and then plug the other end into the built-in port beneath your vehicle's dash.


  • Plug-in wiring adapter allows for quick, simple installation of your electric trailer brake controller
  • No cutting or splicing required
    • Custom connector end plugs into the built-in port beneath the dash of your vehicle
    • Other end plugs into the back of your electric brake controller
  • Compatible with time-delayed and proportional brake controllers from Curt
    • Brake controller must have built-in plug for adapter to connect - will not work on controllers with pigtail wiring harnesses
  • 2' Long, 12-gauge wires have protective covering to deter damage
  • Limited 1-year warranty

Installation of Curt Brake Controller Adapter

To install your Curt electric brake controller, you need to connect the wiring of the controller to your vehicle. Certain auto manufacturers offer pre-wired options, typically known as tow packages, wherein wiring is run for you from the dash to the trailer connector on the back of your vehicle. When this is done, a port is installed at your dash so that you can easily plug in a brake controller.

This adapter plugs into the port on your vehicle's built-in brake control wiring harness. The harness is located underneath the dash, to the left of the steering column, and it is taped to another harness near the emergency brake pedal.

No hardwiring is required to install this adapter. After you plug it into the factory port, you simply plug the other end of the adapter directly into your electric trailer brake controller. Because there are no wires to connect, installation is not permanent. You can unplug and remove your brake controller at any time to transfer it to another vehicle or securely stow it away.

51522 Curt Quick Plug Brake Control Adaptor Harness

Installation Details C51522 Installation instructions

This Product Fits The Following Vehicles

  • 2009 - 2017 Audi Q5 with factory Tow Package
  • 2007 - 2017 Audi Q7 with factory Tow Package
  • 2014 - 2017 Audi SQ5 with factory Tow Package

California residents: click here

Customer Reviews

Curt Custom Wiring Adapter for Trailer Brake Controllers - Dual Plug In - C51522

Average Customer Rating:  4.7 out of 5 stars   (6 Customer Reviews)

Install your Curt electric trailer brake controller quickly and easily with this custom wiring adapter. Simply plug one end of the adapter into your brake controller and then plug the other end into the built-in port beneath your vehicle's dash.

- C51522

This made for an easy plug and play installation—and even included instructions for removal is the lower dash trim panel in my Audi.

- C51522

perfect fit for Audi Q7

- C51522

Bien reste à essayer merci

- C51522

Product is as advertised, functions perfectly, and arrived on time.

- C51522
2019 Porsche Macan

- C51522


Ask the Experts about this Curt Accessories and Parts

  • Plug-In Harness to Install Tekonsha Brake Controller on 2017 Audi Q5
    You are correct that Tekonsha does not currently have a plug-in wiring harness available for your 2017 Audi Q5 but you're also right that you can simply cut off the brake controller end of the Curt # C51522 and hardwire it to the pigtail on your Tekonsha Prodigy P2 # 90885 for installation. You will then still be able to use the vehicle-side plug to connect to the factory port behind the dash of your Audi Q5. After cutting off the controller-side plug on the harness the wires will splice...
    view full answer...
  • Easy to Install Brake Controller for 2014 Audi Q7
    I have a really easy to install brake controller for your 2014 Audi Q7 that works great and is super convenient but the only way to install a Redarc Tow Pro part # RED44FR is going to be by hardwiring the install. Instead check out the Echo Mobile part # C51180. Basically this just plugs into an active 7-way and once you sync it to your phone it's ready to go. This brake controller is proportional which means it senses the amount of deceleration your tow vehicle is applying and applies...
    view full answer...
  • Plug-In Brake Controller Adapter for a 2018 Audi Q5
    I do have a really great alternative brake controller solution for your 2018 Audi Q5 but none of the top brake controller manufactures offers a plug-in brake controller adapter harness like the Curt Custom Wiring Adapter for Trailer Brake Controllers part # C51522 for this vehicle yet. Therefore, you have two options which are to hardwire your own harness in or use a wireless brake controller. If you wish to hardwire your own harness in then you will need to cut the factory plug off the...
    view full answer...
  • Comparing the Curt Spectrum Brake Controller and Redarc Tow-Pro Elite for a 2016 Audi Q5
    Both the Curt Spectrum # C51170 and the Redarc Tow-Pro Elite # RED44FR are excellent brake controller options for your 2016 Audi Q5 but in comparison I recommend going with the Tow-Pro Elite over the Spectrum. Although both controllers can be used as proportional brake controllers (they activate your trailer brakes at the same time and with the same intensity as the brakes on your Q5) the Tow-Pro Elite can also be switched to "User Control" mode which means your trailer brakes will activate...
    view full answer...
  • Brake Controller Installation on my 2017 Audi Q7
    With the Curt Triflex part # C51140 and the Curt Adapter part # C51522 you will have all you need to successfully install your controller. I have linked a video for you showing the operation of the controller. Check it out to familiarize yourself with it.
    view full answer...
  • Recommended Trailer Brake Controller for 2016 Audi Q5 TDI
    If they installed the OEM tow package wiring in your 2016 Qudi Q5 TDI, then there should be the connection under your dash for the wiring harness to be a simple plug and play. The Curt Custom Wiring Adapter for Trailer Brake Controllers # C51522 will have the plug for the factory harness and then you can use the Curt Spectrum # C51170. This proportional controller will have a much cleaner look on your dash so it is what I recommend if you have the plug in harness. If you don't have...
    view full answer...
  • Plug-In Wiring Adapter for Prodigy P3 Brake Controller on 2011 Audi Q7
    Actually there is an adapter from Curt # C51522 that you can use to plug the Tekonsha Prodigy P3 # 90195 directly into your 2011 Audi Q7 if it has the factory 7-Way. You will need to cut the one end off of the adapter and splice the pigtail that comes with the P3 to the adapter (per color) for this to work. If you don't have the factory 7-Way then you will need to run to your local dealer to get parts #1J0-972-782 and #000-979-228 to basically make an adapter (see attached article)....
    view full answer...
  • Will the Curt Echo Work on a 2016 Audi Q5 with the 7 Way Plug Angled Down Slightly
    To start, the Curt Echo # C51180 will work when the 7 way plug in bracket is angled down; this doesn't affect the functionality of the controller and you'll still get responsive braking for your trailer. Part of the appeal of using a wireless controller like the Curt Echo # C51180 is that there isn't any wiring that needs to be done inside the vehicle and it's a simple plug and play installation. The issue with needing a brake controller for vehicles that aren't typically setup for...
    view full answer...

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Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Jameson C
Expert Research:
Jameson C
Employee Cole B
Installed by:
Cole B
Employee Wilson B
Updated by:
Wilson B
Employee Isabelle B
Updated by:
Isabelle B
Employee Kristina F
Written by:
Kristina F

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