Hayes Genesis Trailer Brake Controller - 1 to 4 Axles - Proportional
Universal Wiring Adapter for Hayes Trailer Brake Controllers

Part Numbers: HA81790,HA81789-HBC


Our Price: $138.72

You Save: $14.48

This item qualifies for Free Shipping

In Stock
HA81790 - Under Dash Mount Hayes Brake Controller
zoom in icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.
Please enter a valid email address.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

pop out icon replay 360 icon
horizontal rotate icon

Product Images

In Use/Installed

Customer Photos

Hayes Genesis Trailer Brake Controller - 1 to 4 Axles - Proportional
part number: HA81790

Brake controller engages your trailer's brakes in proportion to deceleration. Mounts within a 125-degree vertical range. Easily adjust power output and braking aggressiveness. Solid-state design with digital display 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 level
    • 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
  • 5 Boost settings let you adjust initial braking power and aggressiveness
  • Easy-to-read digital display communicates brake power output, boost setting, and error codes
  • Easily accessible adjustment buttons let you change settings
  • Built-in safeguards protect your vehicle and trailer
    • 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
  • Slide-bar manual override
  • Dependable solid-state construction
  • Quick and easy installation
    • Mounting bracket and hardware included
    • Plug-in, vehicle-specific brake control adapter (sold separately) can be used for certain applications to reduce installation time
  • Made in the USA


  • Application: trailers with up to 4 axles (8 brakes)
    • Designed for use with electric and electric-over-hydraulic brakes
  • Mounting position: between -35 degrees and 90 degrees in the vertical plane
  • Dimensions: 5-1/8" long x 3-1/4" wide x 1-1/4" tall
  • 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 Genesis 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 accordingly. The result is uniform braking across your towing setup. No push-pull action - just smooth, proportional braking every time.

Built-In Controls on the Genesis

Genesis Diagram

The diagram above shows the controls and components of the Hayes Genesis 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 initial setup process, use the adjustment buttons on the left front of the Genesis controller to adjust the power output. To view the output setting, press either button and release. The output setting will appear as a percentage on the digital display - from 10 to 99. Use the plus and minus buttons to raise or lower the setting in increments of 5.

Power Boost for Heavy-Duty Towing

The Hayes Genesis 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 minus button until the display flashes, then release. Cycle through the available settings (5, 10, 15, 20, or 25) using the minus button and press the plus button to select one. 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 Setting
Much less than the tow vehicle5
Less than the tow vehicle10
Roughly equal to the tow vehicle10 or 15
Slightly greater than the tow vehicle15 or 20
Much greater than the tow vehicle20 or 25

Digital Display

The Genesis brake controller features an easy-to-read LED window that displays the settings as you adjust them.

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 current during trailer set-up or when troubleshooting problems. When the brake pedal is released, the unit will go into standby mode.

The display will also show trouble codes to alert you to any potential problems, such as a short circuit or an open circuit. A code will also appear if the brake controller surpasses its rated power limit.

Slide-Bar Manual Override

The manual slide lever overrides the preset power output and allows the operator to engage the trailer brakes without using the 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.

Quick, Simple Installation

Genesis 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 Genesis 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.

Installation of the Genesis requires that you either purchase a custom wiring adapter designed to plug into the controller or that you hardwire the controller directly into your vehicle. To hardwire the Genesis, 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 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.

81790 Hayes Genesis Electric Brake Controller - Proportional

Universal Wiring Adapter for Hayes Trailer Brake Controllers
part number: HA81789-HBC

Designed for applications that do not come equipped with a brake control wiring harness port from the factory, this adapter plugs into your Hayes electric trailer brake controller at one end and the other end splices into your vehicle's wiring.


  • Universal wiring adapter provides a quick-disconnect for your electric trailer brake controller
    • No need to cut the plug off the brake controller to wire it directly to your vehicle
    • Makes it simple to plug and unplug controller for use in a different vehicle or for storage when you're not towing
  • Wire end splices into your vehicle's wiring
    • Use on a vehicle that does not have a factory tow package or is not equipped with a plug-in port
  • Connector end joins with the plug on your electric brake controller
    • Compatible with time-delayed and proportional brake controllers from Hayes
  • Wire length: 24"
  • Made in the USA

Installation of Universal 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. However, if no port is present, you will have to splice into your wiring.

With this universal adapter, you can install your Hayes brake controller without having to wire the controller directly to your vehicle. If your vehicle has a factory tow package, just splice the pigtail end of the adapter into your vehicle's factory brake control harness wiring, and then plug the other end of the adapter into the controller. If your vehicle doesn't have a factory tow package, you'll have to hardwire the pigtail end of the adapter into your vehicle's wiring. Because only the adapter is hardwired to your vehicle, you can unplug and remove your brake controller at any time to transfer it to another vehicle or securely stow it away.

If your vehicle is not equipped with a factory tow package, you will need to purchase additional equipment to ensure that the signals from your brake controller are sent to your trailer's brakes. We recommend etrailer.com's exclusive 7- and 4-way brake control installation kit (ETBC7 - sold separately).

81789HBC Hayes Universal Pigtail Brake Control Wiring Harness

Replaces 81789-HBC

Video of Hayes Genesis Trailer Brake Controller - 1 to 4 Axles - Proportional

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

Video Transcript for Hayes Brake Controller - Proportional Controller - HA81790 Review

Today, we'll be reviewing Part Number HA81790. This is the Hayes Genesis Trailer Brake Controller for 1 to 4 axles. This is a proportional brake controller. This brake controller activates your trailer brakes in proportion to your vehicle's braking action. So that means it's going to automatically adjust the trailer's braking based on deceleration of the vehicle, and it activates immediately, so there's no pausing like when using time-delayed brake controllers. Inside, there's internal sensors that automatically levels on its own, and that's dependent upon deceleration even if the controller is not mounted level. You can position this anywhere from 35 degrees to 90 degrees in the vertical plane.

Here on the front, it's going to feature adjustable gain settings. It's going to let you determine the power output sent to the trailer's brakes. You can set it higher if towing in hilly terrain or with a fully loaded trailer, or you can back off and lower the power when using or towing a lightweight or empty trailer. It's going to offer 5 Boost settings that let you adjust initial braking power and aggressiveness, has a very easy-to-read LED display on this side here. Over here is the manual override. It's got the easy-to-read digital display that's going to communicate brake power output, boost setting, and error codes.

Again, to adjust between all those, it has these easy push buttons here on the front. Now, this does feature some built-in safeguards that are designed to protect your vehicle and trailer. Manual override is going to illuminate the brake lights on the tow vehicle and trailer. It has a current limiter that's going to protect vehicles from shorts in the trailer wiring. It also has a hazard flasher immunity which means that its going to prevent the pulsing of the brakes when flashers are activated. Again, we have the slide-bar manual override. Very easy to use.

It's a pretty quick and easy installation. It does come with the mounting bracket and the hardware. Hayes also offers plug-in, vehicle-specific brake controller adapters, those are sold separately, that can be used for certain applications to reduce installation time. You can check out our website and see if we have one that's going to fit your application. This is designed to be used with trailers up to 4 axles or 8 brakes, and it can be used with the electric and electric-over-hydraulic braking systems. Go over the measurements real quick of the break controller.

It's going to give us an overall length of 5 and 1/8 inches, an overall width of 3-1/4 inches, and then an overall height of 1-1/4 inches. You also see here on the side that it has multiple options for the mounting bracket. That's going to do it for today's review of Part Number HA81790. This is the Hayes Genesis Trailer Brake Controller.

Customer Reviews

Hayes Genesis Trailer Brake Controller - 1 to 4 Axles - Proportional - HA81790

Universal Wiring Adapter for Hayes Trailer Brake Controllers - HA81789-HBC

Average Customer Rating:  4.8 out of 5 stars   (22 Customer Reviews)

Brake controller engages your trailer's brakes in proportion to deceleration. Mounts within a 125-degree vertical range. Easily adjust power output and braking aggressiveness. Solid-state design with digital display and manual override. Designed for applications that do not come equipped with a brake control wiring harness port from the factory, this adapter plugs into your Hayes electric trailer brake controller at one end and the other end splices into your vehicle's wiring.

- HA81790
by: Bill Clark08/12/2016

Very easy to use. Excellent product ov erall. 283251

- HA81790
by: craig a04/22/2016

Good product easy install. Brake proportion could be more sensitive when braking.... 246440

- HA81789-HBC
by: James11/07/2018

It's a plug and 4 wires. I haven't installed it yet but most likely it will work. It would have been nice if they had the vehicle-specific cable for their brake controller but then maybe my vehicle doesn't have a receptacle (2006 Jeep Commander). Not sure yet, haven't got that far, don't know when I will. I wanted to do it yesterday but it's been cold and rainy here and I don't have room in my garage to work so I've been working on the Jeep in the driveway. I got the trailer hitch mounted the other day and now I'm working on the wiring for the trailer plug. I put the Jeep up on 4 ramps to give me room to get under it and run wiring. At 275 pounds I need the extra space. When the rain stops and the wind dies down I will make an attempt to install this device, but I got this email first asking me for a review and an opinion. I don't really have an opinion yet and I can only write a review of what I know so far, which is very little. The instructions that came with it are quite simple. They tell you to plug it in and then read the instructions that came with the controller that you plugged it into. I was hoping for something more specific, like where should I look for the signal from the brake pedal to the stop lamps. I guess I'll start at the pedal and look for a place to tie in. Maybe YouTube has a video demonstrating the installation procedure for the controller using this Wiring Adapter. That would be nice too. The price for the item was fair, as was the shipping cost and delivery time. No complaints with any of that. I'd share a picture of the product but actually there's one on the page where it is advertised, the page from which I ordered it. I'm not sure why they want me to "share a picture of my product". As for the problem that it solved for me... I didn't have one. It solved that problem. Now I have one. 580967


Thank you for your review. There is not a port to plug a brake controller adapter into on the 2006 Jeep Commander. If the 2006 Jeep Commander has a factory towing package the wires for a 7-way will be ran to the front of the Jeep. You will then use the hardwire adapter part # HA81789-HBC
Universal Wiring Adapter for Hayes Trailer Brake Controllers
to splice into those wires. You will also need part # 5506 to complete the wiring to the battery. If the 2006 Jeep Commander does not have a factory towing package it requires the 7-way plug to be hardwired. In this case an wiring kit part # ETBC7
Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
is needed. The ETBC7 comes with the all of the necessary wiring to wire in the plug and the brake controller. If the vehicle does not have a factory towing package you may also need a 4-way flat connector if you do not already have one. The 4-way connector is part # 118408
T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
for the 2006 Jeep Commander without towing package. I have attached a video of installing a brake controller on a 2010 Jeep Commander with factory wires ran and a help article for the ETBC7 installation.

-- Heather A - 11/08/2018


- HA81790
by: Chris04/20/2019

Given the contradictory information about the availability of the grey connector under the steering wheel for a 2017 Ford Explorer Sport w factory tow package, I ordered the brake controller along with the wiring harness. In previous versions of the Ford Explorer, the plug is there. I took off the plastic cover and the metal plate that sits underneath the steering wheel. The plastic cover has two screws that hold the bottom of it and several push bracket - which was the hardest part to take off without breaking any of the plastic tabs. Once those two things are off tucked underneath the steering wheel is the grey plug. I plugged the wiring harness in, reinstalled the metal plate and the plastic cover. I used one of the holding screws for the plastic cover to attach the bracket for the brake controller (see pic) so that I didn't have to screw into the plastic cover. I was worried I would hit the brake controller with my foot or would be unable to use the hood release, but it sits just fine. Took less than 30 minutes to install. Unlike the last install of a brake controller which took me 7 hours to install all the wiring on my old Volvo XC90. Since I just installed this last night, I have not used it with a trailer. 633621

- HA81790
by: Dave10/21/2018

The controller fired right up and the supplied connector for my wife's 2009 F150 worked fine too. My second order from etrailer. Everything has been great with the exception discussed below - 2009 F150 owners take note - The video showing how to access the 2009 F150 tow package wiring harness plug is for trucks with bench seats. For bucket seats (aka, captain chairs) the plug is still in the location shown in the video, but bucket seat trucks have different dash trim than bench seat trucks. I was not able to fully remove the dash trim that is removed in the video, but was able to pull it away far enough to access the plug. I started removal from the top vice the bottom as shown in the video. That piece of trim has a lip that goes under the instrument cluster trim, but it can be coaxed out from under the cluster trim. Also, it helps to remove the kick plate trim piece near the floorboard to route the wires if mounting the controller on the trim below the steering wheel. The trim below the steering wheel can be removed to drill holes if that's where you're mounting the controller. All the trim pieces described above can be pulled loose by hand with the exception of the trim below the steering wheel which has 3 screws at the bottom. 576367

- HA81790
by: Dennis M09/13/2017

Very easy to install on my 2013 tundra. Just remove inside panel by emergency brake pedal. Plug in , mount were desired, put side cover back on and hook up trailer. Adjust controler and go. 431966

- HA81790
by: Terry06/01/2018

I ordered an after market brake controller that was delivered on the exact date they told me it would arrive. It’s the only controller that will work the electric/hydrolic brake system on my trailer. I have been very pleased with the Hayes genesis controler. 515753

- HA81790
by: Anthony08/20/2018

item exactly as described. arrived quickly. Should be a breeze to install. 555919

- HA81789-HBC
by: Roger07/22/2019

Just traded car in for new one. Much easier to leave old cars wiring alone and add new plug to replacement car. 673514

- HA81789-HBC
by: James06/15/2019

The pig tail was easy to hook up. I was replacing a faulty unit so all the wires were handy. I did not want to do a hard wire in, this made it easy. 658645

- HA81790
by: Brian10/05/2018

This model controller has performed well for my application. 572008

- HA81790
by: Dave G.06/01/2018

I have concluded that there is no reason to shop anywhere except etrailer. They put so much into everything they offer, I don't have to get a forced education on their products. They do the homework. If etrailer says its good, order it, install it, its that easy. Every thing works perfectly! Thank you etrailer. 515012

- HA81790
by: Noel11/08/2017

Once my son-in-law tracked down a burned out fuse and we eliminated the previous owner's wiring mess at the back bumper, the new brake controller and adaptive wiring turned out to be "plug and play" on my '96 F250. Worked just as easily as the wiring harness from etrailer that got me trailer brake lights from my '94 Jeep XJ several months ago. If I need something else for trailers, I'll check etrailer again. 450194

- HA81789-HBC
by: Jack P.01/20/2017

This product makes installing the brake controller so much easier, because I use this unit with multiple tow units it is nice to be able to unplug and move to the other vehicle. 333930

- HA81789-HBC
by: Jon01/10/2017

Came quick, just as ordered. 334694

- HA81789-HBC
by: DAVE12/22/2016

Works great with the Hayes brake controller. Makes older vehicle installation a breeze. 327406

- HA81789-HBC
by: Jerry M06/30/2016

Product arrived in good condition packaged very well as always great service and quick response.Will be buying from E-trailer again. Was able to find a replacement connector for my Hayes brake controller. Thank you keep up the good service. 266706

- HA81789-HBC
by: Bob P.04/10/2016

Made the installation a breeze and allows for the plug and play of the controller when I need it as opposed to the permanent installation of a brake controller in my other pickup. 243612

- HA81789-HBC
by: bill w03/26/2016

Fit good shipped fast thanks good peopl e. 241820

- HA81789-HBC
by: Brad03/03/2016

Product quality and function is every bit as good as expected. 239352

- HA81789-HBC
by: Bruce H05/31/2015

Very pleased with product. Better than the factory of same product. It arrived before estimated date and installation was easy. 199138

- HA81789-HBC
by: Dave W03/09/2015

etrailer.com delivered as promised. Fast friendly service. Product arrived quickly as was exactley what I needed. The how to video was spot on. Thanks, Dave W. 177657


Ask the Experts about this Brake Controller
Do you have a question about this Brake Controller?

  • Troubleshooting OC Code On Hayes Brake Controller With No Trailer Connected
  • The Hayes Genesis Trailer Brake Controller - 1 to 4 Axles - Proportional # HA81790 you asked this from has a code of OC which means Open Circuit. This could mean a problem with the controller internally or it may mean that you have a slight draw on your 7-way due to corrosion. I recommend cleaning your 7-way pins with some sand paper or steel wool and if that doesn't solve your issue then testing your controller. I have attached a video of how to test your brake controller and have also
    view full answer...

  • Recommended Custom Wiring Adapter for Hayes Electric Trailer Brake Controller on 2011 Ford F-150
  • To install the Hayes Genesis Trailer Brake Controller # HA81790 on your 2011 Ford F-150 with tow package, you will use the Custom Wiring Adapter for Hayes Brake Controllers # HA81794-HBC. This harness will install to the factory wiring harness located behind the dash to the right of the steering wheel. I've attached a photo to assist.
    view full answer...

  • Troubleshooting Hayes Genesis Brake Controller HA81790
  • If there is a problem in your Hayes Genesis trailer brake controller # HA81790 that is causing the issue with the truck and trailer brake lights it will probably still occur on the truck alone if the trailer is unplugged. I suggest disconnecting the trailer plug from the 7-way socket and then checking to see if the problem persists. If you can borrow another trailer for testing that can help determine if the problem is on the truck or trailer side. If the truck brake lights behave
    view full answer...

  • Troubleshooting Hayes Genesis Brake Controller That Applies Minimum Braking During Sudden Stops
  • It sounds like your Hayes Genesis Brake Controller # HA81790 is not sensing the deceleration of your truck and trailer so it is not applying more than the minimum braking power when you apply the brakes. During sudden stops you should see the controller the maximum braking power you designate. This typically means that your brake controller is not mounted correctly. Because this controller operates with an internal inertia sensor, it must be mounted between -35 degrees and 90 degrees
    view full answer...

  • Troubleshooting SF Flashing on Hayes Genesis Brake Controller
  • Unfortunately SF is not a reference they have in the owners manual for the Hayes Genesis # HA81790 but I reached out to my tech contact and he said SF stands for Slide Fault. It basically means there is an issue with the manual override slide. He said that if you unplug the unit and let it sit for about 15 minutes then reconnect it a reboot will occur. This may solve the issue, but if the slide fault reappears he said you will need to replace the controller.
    view full answer...

  • Install Harness Recommendation for Hayes Genesis in 2013 Nissan Titan
  • The harness you need is the part # HA81786-HBC which will install the Hayes brake controller part # HA81790 in your 2013 Nissan Titan through the install plug you found under the dash of your truck.
    view full answer...

  • Troubleshooting Genesis Brake Controller that Reads 99 instead of 40 When Braking
  • Have you tried adjusting the gain of the controller down to 40? You probably already tried that but I figured I would at least mention it. What is the angle of the controller? It has to be installed in the range of angles that you see in the attached picture to work properly. Does the controller immediately read 99 when you touch the brakes? That would indicate a short on the brake output circuit most likely to a stoplight circuit. You would need to go over the wiring of the connectors
    view full answer...

  • Troubleshooting OC Code on a Hayes Genesis Brake Controller
  • You wired up your Hayes Genesis Trailer Brake Controller # HA81790 properly to your 2006 Toyota Tundra. The problem is most likely at the 7-way connector at the rear of your vehicle (if there is one). OC would mean open circuit, which means that the trailer is not connected. The brake controller does not recognize a connection to the trailer. On some brake controllers it will also show OC if you are using a brake controller with an electric over hydraulic braking system on your trailer
    view full answer...

  • Flashing OC Code on Hayes Genesis Trailer Brake Controller When Vehicle is Off
  • A brake controller like your Hayes Genesis # HA81790 displays the "OC" message when there is an open circuit, which simply means that the trailer is not connected or the controller does not recognize a connection to the trailer. Since it is coming on when your vehicle is off, I recommend checking the vehicle and trailer connectors for any dirt or corrosion that could be causing this message to appear. Also, simply sliding the manual override on the brake controller all the way, then
    view full answer...

  • Error Code Explanations for the Hayes Genesis Brake Controller part # HA81790
  • I attached a picture that I took from the installation instructions for the Hayes Genesis Brake Controller part # HA81790 that shows what the various codes mean and the possible causes for them.
    view full answer...

  • Recommended Replacement Brake Controller For Malfunctioning Hayes Genesis
  • I see that you had the same issue with your Hayes genesis brake controller # HA81790 before. From the troubleshooting you have done and finding the controller seems to be working now, it sounds as if it is an intermittent issue that may reappear. I recommend replacing the brake controller. I recommend the Prodigy P3 # 90885. This is our most popular brake controller because it is easy to set up and operate. If you want to let me know the year make and model of your truck I can see
    view full answer...

  • Hayes Genesis Trailer Brake Controller Flashing OC on Display Screen in 2002 Ford Explorer
  • I looked into the operating manual for the Hayes Genesis Trailer Brake Controller # HA81790 and it looks like when "OC" is flashing on the display, it indicates that either there is no trailer connection detected or the trailer has electric over hydraulic brakes, with which the Genesis is not compatible. If your trailer does not have electric over hydraulic brakes, check to make sure all the connections running back to your trailer are secure and correct. The other possibility is that
    view full answer...

  • Troubleshooting a Brake Controller that is Sending Max Voltage on Brake Output Circuit
  • Sounds like you need to test the brake controller so we can narrow down where the problem is. Testing the brake controller is fairly easy. Sever the blue brake output wire near the brake controller leaving enough room to reconnect it and then apply the manual slide. Using a circuit tester like the Quickee Tester, part # PTW2993, you should get output to the controller side of the wire you severed. If the manual slide activates the trailer brake output wire properly, try the brake pedal.
    view full answer...

  • Troubleshooting Trailer Brakes that Lock Up
  • Since you've already checked the setting on the brake controller the next thing is to check the adjustment of the brakes. I've linked a video and if you skip ahead to around the 4:30 mark you'll see the brakes being adjusted. You should also inspect the wiring starting at the connectors to make sure there are no shorts. Look for corrosion in the connectors or any pinched or exposed wire. If you still can't find the problem let me know what you have found and we'll continue to troubleshoo
    view full answer...

  • Will Hayes Brake Control Suffer RF interference and Overheating
  • I spoke with my contact at Hayes and he said the Hayes Genesis Trailer Brake Controller # HA81790 will not suffer any interference from cellphones, CB radios, etc. Based on my research most manufacturers of brake controllers insist on 12 to 18 inches of separation between CB radios and their brake controllers. I suggest mounting the brake controller and radio as far as possible away from each other to avoid interference when the brakes are applied. Distance is the key to keeping the electrical
    view full answer...

  • Does Computer have to be Flashed to Install a Brake Controller in a 2016 Ford F-150
  • You will not have to flash the computer on your 2016 Ford F-150 to install the Hayes Genesis brake controller # HA81790. I do recommend using the vehicle specific wiring harness # HA81794-HBC instead of a universal one that you would have to splice into the Ford harness. If you use the vehicle specific harness you can just plug the controller straight into the truck without having an intermediate harness between the 2.
    view full answer...

  • Troubleshooting Blinking OC on Hayes Genesis Brake Controller on 2001 F-350 7.3L
  • Your Hayes Genesis Trailer Brake Controller # HA81790, has OC flashing which means Open Circuit. This means it is not recognizing a trailer connected and yet is recognizing a draw in power from the controller. This most likely means that the 7-way has some corrosion on the pins that needs cleaning or there is not a solid ground either at the 7-way or back at the brake controller itself. To clean your 7-way pins, I recommend using some light sand paper. To ensure you have a good
    view full answer...

  • Troubleshooting Short-Circuit Code on Hayes Genesis Trailer Brake Controller HA81790
  • If three identical Hayes Genesis # HA81790 brake controllers have had the same issue with displaying the short-circuit (SC) code after a few months of operation, then I would consider carefully inspecting the trailer and vehicle connectors for signs of corrosion, trapped dirt or moisture that could be causing a short. Corrosion in a connector can cause two circuits to become bridged together; this could easily cause the SC error code. You can also make sure the brake circuit wire has
    view full answer...

  • Trailer Brakes Come On at Full Power No Matter What the Brake Controller is Set To
  • There are a couple of things that could be causing the brakes to come on at full power when you step on the brake pedal. First, make sure the brake controller is mounted within its range specified in the instructions. Also make sure it is not tilted or turned to one side. If it is outside of its range that can cause the controller to think that you are braking more aggressively than you are (and sometimes it will do the exact opposite). There could be a short somewhere. Check the vehicle
    view full answer...

  • Hayes Brake Controller Showing Higher Output than What the Controller is Set To
  • The Hayes Genesis brake controller # HA81790 is compatible with electric over hydraulic brakes but it should not take 4 seconds for the brakes to actuate. I would double check the instructions for set up to make sure your controller is set up for electric over hydraulic mode. If the controller is mounted outside of its range specified in the instructions then that can cause all sorts of strange things to happen. Brake controllers can get bumped accidentally so this is a possibility.
    view full answer...

  • Wiring Adapter for Hayes Lemmerz Energize III Brake Controller on a 2012 Chevrolet Suburban
  • The adapter you are looking for is the # HA81789-HBC. This universal harness will need to be hardwire installed for your 2012 Chevrolet Suburban. Hayes does not offer a wiring harness that will plug into the brake controller port under the dash, if your vehicle has one. I have attached a Help Article on installing a brake controller on your vehicle for your convenience.
    view full answer...

  • How to Install and Remove the Connector on Hayes Universal Wiring Adapter # HA81789-HBC
  • The Hayes Universal Wiring Adapter # HA81789-HBC that you referenced is intended to plug into the back of a compatible Hayes brake controller such as their Genesis # HA81790 and then hard-wire to your vehicle using the 4 wire leads. The plug portion on the adapter is not intended to mate with any connectors on your 2007 Dodge Ram 2500 Pickup. There are other brands of brake controllers that do use adapters with plugs on both ends, one for the controller and one for the vehicle, such
    view full answer...

  • Installing Hayes Energize III Brake Controller on 2012 Chevrolet Silverado
  • To install your Hayes-Lemmerz Engerize III 81741B in your 2012 Chevrolet Silverado, you will want to use the Hayes Universal Wiring Adapter # HA81789-HBC. This universal adapter will need to be hardwire installed for your Silverado. Hayes does not offer a wiring harness that will plug into the brake controller port under the dash, if your truck has one. I have attached a help article on installing a brake controller in a 2007-2013 Silverado for you. This help article will walk you
    view full answer...

  • Trailer Wiring Harness to Install Hayes Brake Controller on 1996 GMC K1500
  • For the Hayes Energize XPC brake controller the wiring harness that connects into the wiring of your 1996 GMC K1500 is # HA81789-HBC. It needs to be hardwired into your truck with the black wire going to 12 volt power, white to ground, the blue goes to the rear of your truck to power the trailer brakes, and the red connects to the stop light switch which is the wire coming from the truck's brake pedal connector that is hot only when the pedal is pressed. You can test this with a circuit
    view full answer...

Info for these parts were:

Edited by:
Lindsey S
Expert Research:
Michael H
Expert Research:
Jameson C
Expert Research:
Adam R
Updated by:
Laura H
Installed by:
Cole B
Expert Research:
Jeffrey L
Photos by:
Sam P
Written by:
Tammy D
Updated by:
Sarah W
Photos by:
Zach O

At etrailer.com we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.