1. Accessories and Parts
  2. Hayes
  3. Trailer Brake Controller
  4. Wiring Adapter
  5. Plugs into Brake Controller
  6. Vehicle Specific
Custom Wiring Adapter for Hayes Brake Controllers - Dual Plug

Custom Wiring Adapter for Hayes Brake Controllers - Dual Plug

Item # HA81785-HBC
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Hayes Trailer Brake Controller - HA81785-HBC
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Install your Hayes electric trailer brake controller quickly and easily with this custom wiring adapter. One end plugs into the controller, and the other plugs into the built-in port beneath your vehicle's dash. Call 800-298-8924 to order Hayes accessories and parts part number HA81785-HBC or order online at etrailer.com. Free expert support on all Hayes products. Guaranteed Lowest Price and Fastest Shipping for Custom Wiring Adapter for Hayes Brake Controllers - Dual Plug. Accessories and Parts reviews from real customers.
  • All Info
  • Reviews (11)
  • Q & A (10)
  • Photos
  • Why etrailer?

Hayes Accessories and Parts - HA81785-HBC

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

Install your Hayes electric trailer brake controller quickly and easily with this custom wiring adapter. One end plugs into the controller, and the other plugs 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
    • Opposite end plugs into the back of your electric brake controller
  • Compatible with time-delayed and proportional brake controllers from Hayes
  • Made in the USA

Installation of Hayes Brake Controller Adapter

To install your Hayes 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, in which the wiring is run for you from the dash to the trailer connector on the back of your vehicle. Usually 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 5-pin connector on your vehicle's built-in brake control wiring harness. The harness is located underneath the dash, to the left of the steering column, 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.

81785HBC Hayes Dual-Mated Brake Control Wiring Harness - Toyota and Lexus

Replaces 81785-HBC

This Product Fits The Following Vehicles

Customer Reviews

Custom Wiring Adapter for Hayes Brake Controllers - Dual Plug - HA81785-HBC

Average Customer Rating:  4.8 out of 5 stars   (11 Customer Reviews)

Install your Hayes electric trailer brake controller quickly and easily with this custom wiring adapter. One end plugs into the controller, and the other plugs into the built-in port beneath your vehicle's dash.

- HA81785-HBC
2013 Toyota Tundra

Perfectly fit harness made hooking up my brake Controller a breeze in my 2013 Tundra. The 4 pin quick fix flat connector worked decent ... a little tricky getting it snapped together after all 4 wires were in place as it appears it was not designed for this gage of wire but it did the job.. 478798

Still working out perfectly!!
Todd - 02/26/2019


- HA81785-HBC
2015 Toyota Tacoma

Easy install in my 2015 Tacoma with factory towing package. 817709

- HA81785-HBC
Toyota 4Runner

Worked perfect with my brake control system for my Toyota 4runner. It was a great price and will definitely shop with etrailer again. 678723

- HA81785-HBC

Viewed installation and they recommended a patch cord to connect the brake. Glad I took their advice and ordered one. Called etrailer and spoke with Nicolas and he found the right cable for my truck in seconds and shipped it. Installed it in a matter of minutes. Good call on my part, no brainer to install. 677841

- HA81785-HBC
Toyota Tundra

Wasn't sure which harness to buy for my Toyota Tundra so I called and spoke with Donna in customer service. She looked up the right part #, three days later it was in my mailbox and one day later it was installed. I have purchased from etrailer before and have always been highly satisfied. Great place to do business with! 650595

- HA81785-HBC
2012 Toyota Tundra

The install cable that I ordered for my 2012 Tundra clicked right into place and allowed me to install my electric brake controller in minutes. Thank you guys for an accurate part number, order processing, and easy delivery! 604712

Still working like a champ!
Darren - 02/14/2020


- HA81785-HBC
2005 Toyota Tacoma

The harness worked as it was advertised. The service was fantastic 513839

- HA81785-HBC

Ty for following up with your product that we purchased si far so good* 351736

- HA81785-HBC

Super easy 317908

- HA81785-HBC
2010 Toyota Tundra

Searched Auto part stores for brake controller conversion cable to mount brake controller from 2001 Toyota Tundra to 2010 Toyota Tundra with no luck. Searched internet and found E Trailer. Search on E Trailer was easy, as was ordering. Part fit perfectly. 201048

- HA81785-HBC
2008 Toyota Tacoma

Worked like a charm. 176796


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Info for this part was:

Edited by:
Lindsey S
Expert Research:
Michael H
Expert Research:
Jameson C
Expert Research:
Adam R
Updated by:
Laura H
Updated by:
Sarah W
Installed by:
Cole B
Written by:
Tammy D

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