Hayes G2 Brake Boss Trailer Brake Controller w/ Mounting Sleeve - 1 to 4 Axles - Proportional
Custom Wiring Adapter for Hayes Brake Controllers - Dual Plug

Part Numbers: HA81792BB,HA81787-HBC

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Hayes Dash Mount Trailer Brake Controller - HA81792BB
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Hayes G2 Brake Boss Trailer Brake Controller w/ Mounting Sleeve - 1 to 4 Axles - Proportional
part number: HA81792BB

Brake controller engages trailer's brakes in proportion to deceleration. Mounts with included sleeve within a 125-degree range. Easily adjust power output and braking aggressiveness. Includes digital display, audible alert, and manual override.


  • Brake controller activates trailer brakes in proportion to your vehicle's braking action
    • Automatically adjusts trailer's braking based on deceleration of tow vehicle
    • Activates immediately - no pausing like with time-delayed brake controllers
  • Automatically levels - internal sensor detects deceleration even if controller is not mounted flat
    • Position anywhere from -35 degrees to 90 degrees in the vertical plane
  • Adjustable gain setting lets you determine the power output sent to the trailer's brakes
    • Set to higher output when towing in hilly terrain or with a fully loaded trailer
    • Back off power when towing a lightweight or empty trailer
  • 4 Boost settings let you adjust initial braking power and aggressiveness
  • Large, easy-to-read LCD screen communicates brake power output, boost settings, and error codes
    • High-resolution screen is glare resistant
  • Easily accessible adjustment buttons let you change settings
  • Built-in safeguards protect your vehicle and trailer
    • Audible alert warns driver about wiring continuity problems
    • Manual override illuminates brake lights on tow vehicle and trailer
    • Current limiter protects vehicle from shorts in the trailer wiring
    • Hazard flasher immunity prevents pulsing of the brakes when flashers are activated
  • Bottom-mounted, slide-style manual override
  • Quick and easy installation
    • Plug-in, vehicle-specific brake control adapter (sold separately) can be used for certain applications to reduce installation time
  • Mounting sleeve attaches to tow vehicle's dashboard with 3M VHB tape - no drilling required
    • Allows the brake controller to be easily removed for storage or for use in a different vehicle
  • Made in the USA


  • Application: trailers with up to 4 axles (8 brake assemblies)
    • Designed for use with electric or electric-over-hydraulic brakes
  • Mounting position: between -35 degrees and 90 degrees in the vertical plane
  • Dimensions: 5" long x 3-1/4" wide x 1-1/4" tall
  • Limited lifetime warranty

Proportional Braking

With a proportional brake controller, you can get heavy-duty emergency braking, general braking, or slow-to-an-idle braking for your trailer automatically. The intensity with which your trailer brakes are activated and the rate at which they are applied are dependent on the deceleration of your tow vehicle. This means that, unlike time-delay controllers - which send the same amount of preset power to your trailer brakes every time - proportional controllers are able to adapt to every braking situation differently.

So, if you slam on the brakes in your truck, your trailer brakes will activate with that same extreme intensity. And if you merely slow down as you approach a red light, your trailer will gradually brake in the same manner.

As long as the Brake Boss is properly mounted according to the included instructions, the controller will automatically level, sense the tow vehicle's deceleration, and adjust the trailer's braking. The result is uniform braking across your towing setup. No push-pull action - just smooth, proportional braking every time.

Built-In Controls on the G2 Brake Boss

G2 Brake Boss Controls

The diagram above shows the controls and components of the Hayes G2 Brake Boss electric trailer brake controller.

Power Output Control

The power output control lets you set the maximum amount of power that will be applied to your trailer's brakes. Typically, the power output is only readjusted if you switch from a heavy, loaded trailer to a much lighter, empty trailer - or vice versa.

During the installation setup process, use the adjustment buttons on the front right side of the G2 Brake Boss controller to adjust the power output. To get more power to your brakes, press the "up" button. To decrease the power output, press the "down" button. The output can be raised or lowered in 5-percent increments.

Power Boost for Heavy-Duty Towing

The Hayes G2 Brake Boss also offers a boost feature that gives you more initial braking power for those times when you're towing heavy loads or a larger trailer. You can switch boost levels so that the power output to your trailer brakes automatically starts out at a set percentage of the predetermined power setting.

If you're towing a heavy load, sending out more initial power to the trailer brakes - and causing them to reach maximum braking faster - allows you to better control the trailer so it doesn't push your tow vehicle before coming to a complete stop.

To set the initial power, press the menu button and select from one of the available settings. (B0 is 0 percent, B1 is 5 percent, B2 is 10 percent, B3 is 15 percent, B4 is 20 percent.) The higher the setting, the more aggressive the braking will be. Hayes makes the following recommendations for which boost setting(s) to use with your towing setup:

Approximate Gross Trailer WeightBoost SettingIncrease in Initial Power Output
Much less than the tow vehicleB0 or B10 percent or 5 percent
Less than the tow vehicleB210 percent
Roughly equal to the tow vehicleB2 or B310 percent or 15 percent
Slightly greater than the tow vehicleB3 or B415 percent or 20 percent
Much greater than the two vehicleB420 percent

Digital Display

The G2 Brake Boss features a large LCD display where the brake type, power output, boost settings, alarms, and diagnostics are shown. You can set the color, intensity, and contrast on the display.

While braking, the display shows the amount of power going to the trailer brakes as a percentage of the total available. You can change this display to show voltage or amperage during trailer set-up or when troubleshooting problems.

The Brake Boss will display the word "Warning" when it senses problems, and it will help you troubleshoot these problems by indicating the following: Output Short - No Brakes, Overload - Excessive Amps, No Trailer, or Blue Wire Fault - Voltage Present. The controller will deliver an audible alert when these warnings display, unless you choose to turn it off.

Slide-Lever Manual Override

The manual slide lever is located on the bottom of the unit. To activate it, just pull the lever forward. The manual slide lever overrides the preset power output and allows the operator to engage the trailer brakes without using your vehicle's brakes. In addition to being a necessary safety feature, this option helps to control trailer sway by slowing the trailer to put it back solidly behind the tow vehicle.

You can also engage the manual override to help you move a sliding 5th-wheel hitch closer to your truck's tailgate for tight maneuvering during slow speed turns. Just apply the manual override to hold the trailer in place while slowly moving the tow vehicle forward.

Installation and Wiring

G2 Brake Boss Mounting Angles

Because this controller operates with an internal inertia sensor, it must be mounted between -35 degrees and 90 degrees in the vertical plane. The G2 Brake Boss must be mounted on a level horizontal (side-to-side) plane and must be lined up with the direction of travel for the internal sensor to function properly.

The Brake Boss comes with the Hayes Quik-Receiver. The Quik-Receiver is a mounting sleeve that attaches to your dashboard with 3M VHB tape - no drilling is required. With the Quik-Receiver you can easily remove the Brake Boss for storage or transfer it to another tow vehicle. A replacement wiring harness (sold separately) and a replacement Quik-Receiver bracket (sold separately) are required to move the controller from one vehicle to another.

Installation of the G2 Brake Boss requires that you either purchase a custom wiring adapter designed to plug into the controller or that you hardwire the controller directly into the vehicle. To hardwire the Brake Boss, you must remove the plug at the end of the integrated wiring harness.

Installation Accessories

The Hayes vehicle-specific, dual-mated wiring adapter is available for most newer trucks and SUVs with tow packages. One end of the custom adapter plugs into your vehicle's brake controller port, and the other end plugs into the controller - no hardwiring required.

Hayes also offers a universal wiring harness (HA81789-HBC - sold separately) that plugs into the back of any Hayes brake controller. The 4 leads on the universal harness can then be hardwired into your vehicle. By splicing the universal adapter into your wiring instead of directly connecting the brake controller to your wiring, you gain the ability to unplug and remove the controller from your vehicle should the need arise.


  • If a custom brake-control wiring adapter is not available for your vehicle, one of the following will be required:
    • 20-Amp circuit breaker (9506P - sold separately) for 2-brake applications
    • 30-Amp circuit breaker (38630 - sold separately) for 4- to 6-brake applications
    • 40-Amp circuit breaker (9510 - sold separately) for 6- to 8-brake applications
  • If you're hardwiring the controller, it is also suggested that you install an in-line fuse between the controller and the stop light switch (required on 1999 and newer Fords).

See also etrailer.com's exclusive 7- and 4-way brake control installation kit (ETBC7 - sold separately) if you don't already have a 7-way plug at the back of your vehicle.

81792BB Hayes G2 Brake Boss Electric Brake Controller w/Bracket - Proportional

Custom Wiring Adapter for Hayes Brake Controllers - Dual Plug
part number: HA81787-HBC

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 4-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.

81787HBC Hayes Dual-Mated Brake Control Wiring Harness - Honda

Replaces 81787-HBC

Customer Reviews

Hayes G2 Brake Boss Trailer Brake Controller w/ Mounting Sleeve - 1 to 4 Axles - Proportional - HA81792BB

Custom Wiring Adapter for Hayes Brake Controllers - Dual Plug - HA81787-HBC

Average Customer Rating:  4.7 out of 5 stars   (14 Customer Reviews)

Brake controller engages trailer's brakes in proportion to deceleration. Mounts with included sleeve within a 125-degree range. Easily adjust power output and braking aggressiveness. Includes digital display, audible alert, and manual override. 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.

- HA81792BB
by: Bobby J10/02/2019

Installation was easy, just plug and play. No issues so far. 715343

- HA81792BB
by: Mike S03/24/2015

The Hayes G2 was very simple to install in my 2012 Ram 1500. The two sided tape did not hold for me, probably the cold temps up here in upstate NY, but I was able to use the included screews to secure the cradle. The bundled wiring adapter made the installation plug and play, so much easier then the old pigtails and electric tape. The factory default of 50% power and 10% gain should be about what I need to handle my nearly 3000 lb (fully loaded) pop-up but I will be able to fine tune that once I am able to have a proper test drive. I am very pleased with this controller so far. Can't wait for our first trip of the season! 180578

- HA81792BB
by: RonnieMX08/12/2016

First of all I'd like to say kudos to e-trailer for getting a brake controller and wiring to my house in Vermont from their place in Missouri overnight. I was shocked when It got here so fast, they saved my vacation. I really like the Hayes brake controller it works very well and is predictable. It's also very easy to set up once it's all connected. It was a breeze to install particularly on my 2006 Nissan Titan, it was two plugs, and stick it on the dash, and I was done. The only thing I need now is a bigger better truck to pull my 8000 pound trailer up to the speed limit, never did make it. The Nissan is a bit week for the job and it overheated a couple of times on hills and I had to turn on the heater to drain extra heat and bring the temperature back down, no AC allowed. But the trip went well nonetheless. My next truck will be diesel with dual wheels four-wheel-drive, no monkeying around next time. Thanks e-trailer! I'll be back to get my gear for my next truck from e-trailer for sure?? 283092

- HA81792BB
by: Tony04/24/2020

Very small and very easy to install and mount !! I am a 25 year auto mechanic and tell you any one can install this brake product... 10 min. install time. and will display in several colors. The green display was easy for me to see.. have not pulled my trailer yet but a easy install and mount in a covey hole like it is a factory piece. Rev. Tucker 785178

- HA81792BB
by: Barry02/23/2020

Great product, easy to install 757529

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by: John02/23/2020

Easy install, perfect size for my Titan. 757400

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by: Alan08/27/2019

This was an awesome product 5-minute install on my 2019 Ram 1500 cannot wait to put it to use 694462

Working great ??
Alan M - 08/28/2020

Works awesome
Alan M - 08/28/2020


- HA81792BB
by: Works perfectly07/15/2019

Mounting and connection are easy if you have the factory tow wiring. Works perfectly controlling the brakes 670611

- HA81792BB
by: Rickey06/06/2019

Very timely delivery, everything arrived on time just as I was told. Very quick and easy installation in my 2017 Dodge Ram. 654252

All is great after a year of use.
Rickey P - 06/07/2020


- HA81787-HBC
by: PaulG03/12/2018

Found the correct part quickly , fast delivery and worked just as it should! 484080

it worked fine until I sold the vehicle it was designed for! Now I am going to cannabilize it and hook up the controller to a different vehicle. I hope
PaulG - 03/15/2019


Sound like a plan. If you need to reference I have included a link to our help article that indicates how to install a brake controller from scratch. You would want to reference the diagram at the bottom of the page that shows the brake controller output wiring configuration.

-- Rachael H - 3/15/2019

- HA81787-HBC
by: Lydia12/12/2017

Everything worked well. Thanks. 459538

- HA81792BB
by: kent09/23/2017

Good install info. Easy hook-up. Plan on hauling hay tomorrow so will give it a good test. 435785

- HA81792BB
by: Jon01/10/2017

Came quick, just as ordered. 331554

- HA81787-HBC
by: Andy s07/20/2014
2014 Honda Odyssey

Easy install. 142319


Ask the Experts about this Trailer Brake Controller

  • Brakes Will Not Release and Brake Lights Stay On Using Manual Override On Hayes G2 Brake Boss
  • If the manual override is not releasing then I am afraid there is an internal error on the Hayes G2 Brake Boss Trailer Brake Controller part # HA81792BB and it will need to be replaced as brake controllers are not repairable. The brake lights are staying on because the brake controller sends a signal to these lights with the manual override applied. For replacement, I recommend upgrading to the Hayes Genesis Trailer Brake Controller part # HA81790 which will use the same plug as your
    view full answer...

  • What Angle Does the Hayes G2 Brake Boss Have to Be Installed at for Proper Function
  • The Hayes G2 Brake Controller part # HA81792BB has to be installed in a specific angle range otherwise the proportional sensors of the controller will not accurately be able to sense braking activity and apply the correct amount of braking power to the trailer. If the controller being totally level and squarely facing the rear of the vehicle it is 0 degrees, then 94 degrees would be slightly past totally vertical and -35 degrees would pretty close to the middle of facing directly at
    view full answer...

  • Hayes G2 Brake Boss Controller with Brake Controller Adapter for 2001 Chevrolet Silverado
  • Yes, the brake controller adapter is included with the brake controller if you go through the Fitguide on the website with the 2001 Chevrolet Silverado and click on brake controller. The Hayes brake controller is part # HA81792BB. The brake controller adapter part # HA81781-HBC plugs into the junction box under the dash of the Chevy and the other end plugs into the Hayes brake controller. If your truck has a 7-way the Hayes brake controller and adapter are all you need. If your Chevy
    view full answer...

  • Fit of Hayes G2 Brake Controller # HA81792BB on 2004 Ford F150
  • A brake controller isn't a vehicle-specific item, so the Hayes G2 brake controller you mentioned, part # HA81792BB would work just fine. You would need a wiring adapter, part # HA81783-HBC that would plug into the rear of the controller and into the connector located under the vehicle dashboard. As you can see in the provided photo, the brake controller is located behind the OBD port under he steering column. It's located above the OBD port and to the right.
    view full answer...

  • Brake Controller Port Location in 2016 Ram 1500 Laramie
  • Often a brake controller connector will be tucked up pretty high and out of the way, and sometimes it will even be taped to other wiring or other components behind the rear side of the dash. It can definitely be hard to spot them sometimes. There may be a foam wrap or cap on the connector to protect its electrical contacts. The vehicle's trim level, such as the Laramie edition, generally does not affect internal components like wiring parts.
    view full answer...

  • Troubleshooting Brake Controller Install that Activates Vehicle Brake Lights When Connected
  • Sounds like the wiring of your Hayes G2 Brake Boss Trailer Brake Controller # HA81792BB needs to be checked. Can you verify that the black wire of the controller is ran to a 12 volt power source, the red to a circuit that only sees voltage when the brakes are applied and the blue to the output circuit of your 7-way? The white should also be grounded but since your controller is coming on it sounds like that circuit is properly connected.
    view full answer...

  • Troubleshooting Trailer Brakes That Intermittently Lock Up With any Brake Pressure
  • Sounds like the problem is on the trailer's wiring as the issue you are having has shown up with two different tow vehicles. The most likely situation you have is that your brake light circuit is shorting out to your brake output circuit which is causing your trailer brakes to apply fully when the brakes are applied. Do you notice the brakes applying or locking up when the blinker is applying as well? If so, that blinker circuit on your trailer wiring is shorting to the brake output
    view full answer...

  • Is Hayes G2 Brake Boss Trailer Brake Controller HA81792BB Made in the USA
  • Yes, the Hayes G2 Brake Boss Trailer Brake Controller # HA81792BB is made in the USA. In comparison to the Draw-Tite I-Command # 5535 (which is not USA-made) the Hayes allows for a wider range of installation positions, anywhere from -35 degree to +90 degrees in the vertical plane. The Draw-Tite requires a slightly tighter installation range of -20 to +70 degrees. Both work with electric and electric-over-hydraulic brakes on up to 4 axles and both are covered by a limited lifetime warranty.
    view full answer...

  • Troubleshooting Output Short Message on Hayes G2 Brake Brake Boss Controller part # HA81792BB
  • The message you are seeing on your Hayes G2 Brake Controller part # HA81792BB indicates that there is a short on the brake output circuit of the brake controller. Since it is showing this code with the trailer disconnected that would mean the problem is on the truck like you suspected. Commonly this is due to corrosion on the trailer connectors. This can be fixed by hitting the connector with some fine grit sandpaper. Aside from that you will need to trace the wiring from the brake
    view full answer...

  • Installation of Hayes G2 Brake Boss Trailer Brake Controller on 2004 Ford Ranger
  • We do have a video of a brake controller being installed in a 2002 Ford Ranger but it's not the Hayes G2 Brake Boss, part # HA81792BB. With that being said since the truck is the same generation as your 2004 and brake controllers are universal as far as the installation goes the process is basically the same. The video also uses our installation kit, part # ETBC7, which you'll need if your Ranger doesn't have a 7-way connector. The kit installs into an existing 4-way converting it
    view full answer...

  • Parts Needed to Install Brake Controller On 2008 Hyundai Veracruz
  • To install the Hayes Trailer Brake Controller # HA817922BB, you will want to use the Hayes Universal Wiring Adapter # HA81789-HBC. This pigtail will splice into your vehicle. The white wire needs to be grounded. The black wire will connect to the battery. The red wire goes to the stoplight wire. The blue wire is connected to the trailer connector at the rear of the vehicle. You will also need a wiring harness for your vehicle if you don't already have one. I recommend the Tow Ready
    view full answer...

  • Hayes G2 Brake Boss Trailer Brake Controller Recommendation for a 2011 Jeep Grand Cherokee
  • Yes, you can install the Hayes G2 Brake Boss Trailer Brake Controller w/ Mounting Sleeve # HA81792BB in your 2011 Jeep Grand Cherokee. The connector should be mounted on top of the emergency brake bracket, it's gray in color. Once you find it all you need to do to install this controller is plug the Custom Wiring Adapter for Hayes Brake Controllers # HA81796-HBC into the port under your dash and then plug the other end into the # HA81792BB, mount it, and you'd be good to go.
    view full answer...

Info for these parts were:

Edited by:
Lindsey S
Updated by:
Laura H
Updated by:
Sarah W
Installed by:
Cole B
Written by:
Tammy D

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