HomeRV Hitch & TowHow Does Electric Trailer Brakes Work?

    How Does Electric Trailer Brakes Work?

    In today’s modern technology people have the term “Brake-by-wire” – electric brake. Electric brakes are standard to use on your trucks or trailers and they have the use as hydraulic brakes on cars.

    We believe that drivers already know how hydraulic brakes work in normal cars. For an extremely heavy trailer with a weight of 15000 to 20000 pounds, how do trailer brakes work? We’re gonna walk you through the topic about electric trailer brakes

    Electric Trailer Brakes : Basic Knowledge.

    Getting your truck and trailer braking balance is very important particularly if you end up in some sort of emergency braking situation. How to stop your trailer as efficiently as possible? Electric trailer brakes not only do a good job of helping your trailer stop but it’s also considered a vital key to giving drivers a safe towing experience.

    With increasingly developed technology, the electronic brake system has reduced complicated brake movements, instead, it is a control signal system that receives and outputs signals to control the brake mechanism. 

    The only difference between the electric brake and mechanical is that electric brakes use electromagnets while mechanical brakes or hydraulic brakes use the pressure powers to brake your car.

    Let’s find out the main parts that make up the electric brakes for trailers. The electric brake system has several components, including a reactor spring, adjuster spring, primary shoes, larger secondary shoes, actuating arm, and a magnet.

    All of these parts are combined and work seamlessly to support overall functionality.

    how electric trailer brakes work

    Read more: Best Brake Pads For Towing

    What is the trailer brake controller system?

    In order to safely tow heavy loads, many trailers are equipped with electrically operated brakes when connected to the vehicle equipped with an electronic trailer brake controller. And we must say that: your brake trailer can’t operate if you don’t install the brake controller first.

    Currently, in some states, drivers are required to have trailer brakes and a device called a brake controller. How does the device work? When drivers step on the brake pedal in their truck, the trailer brake controller tells the trailer’s brakes how much braking force is needed to stop the trailer.

    Essentially, a brake controller is a device that sends the power down to a set of electromagnets. You can increase or decrease the amount of power going to that magnet and essentially give more or less braking force to the trailer to assist the vehicle stopping. 

    How many types of brake controllers? 

    There are actually a number of different brake controllers on the market now, but in the article, we will divide brake controllers into 2 distinct types:

    Proportional brake controllers

    Proportional brake controllers are activated by the brake pedal switch and a pendulum-type circuit that senses the speed of the stopped vehicle and puts a proportional voltage to the trailer brake. This type of brake controller uses a motion sensor to determine the deceleration of your vehicle because the sensor detects the motion it needs to be mounted in a certain way.

    The sensor will activate the trailer’s brake evenly with the vehicle brakes by detecting how quickly the vehicle is operating whether it’s a slow stop or a sudden stop. 

    The main advantage of the proportional brake controllers is that they provide smooth braking because this brake controller can reduce the amount of wear on both towing vehicles and trailer brakes. Beside the positive features, the proportional controller also have the disadvantage that you should consider before deciding buy it:

    • More expensive compared to other brake controllers
    • A little bit complex when you install it.

    Let’s move on to the other type of brake controller:

    Time-delayed brake controllers

    They are also referred to as: time actuated or solid-state controllers. These controllers can be mounted at any angle as they don’t have a motion sensor built in. You can adjust the amount of power being sent to the trailer brakes. This brake system operates on a predetermined brake capacity set by the user and based on the weight of the trailer plus the weight of the expected cargo. Drivers can easily adjust the braking force and time with a “sync” button that is designed for every time-delayed controller.

    Time-delayed controllers are great for customization but just remember to change your settings depending on how heavy your haul is? Contrary to the proportional controllers, time-delayed brakes are a bit less expensive and they are easy to install. However, one disadvantage of this type of brake is that: it can cause wear and tear on the brake system.

    How Electric Trailer Brakes Work?

    The main prerequisite in using the electric trailer brake is that you have a tow vehicle equipped with a brake controller. Electric trailer brakes are installed in the wheel assembly of your trailer. The brake and a trailer must be connected electrically via a wire, in order to function. This wire is coming from the truck and this truck will provide a voltage to the magnet of your electric brake. The higher the voltage it provides the more current the magnet draws. 

    Electric trailer brakes use an electromagnetic drum to slow down or stop the rotation of the trailer wheels. The brake controller, mounted inside the tow’s cab, is used to activate the electric brake system. In the stages, the brake controllers will distribute and adjust the amount of power moved from the tow vehicle to the electric brake of your trailer. Power to the brake is controlled through the brake controller and brake light circuit.

    When the light is on and the brake controller activates. It will send power down a separate heavy-duty circuit to the trailer brake system. Because electric brakes only activate when the tow’s brakes are in use, they remain active on rough, uneven terrain.

    When you hit the brake, the brake light activates. Simultaneously, a voltage is sent to the trailer’s magnet, which then activates the brakes. You can activate the electric brake with a lever or a manual button, giving you maximum control over the trailer’s braking system.

    The electric brake system has some upsides, such as limiting pressure on the trailer’s brakes and the ability to manually adjust it via the brake control to reduce sway, which is a big plus when driving on hills. In general, electric brakes can work effectively when they are calibrated properly, however, sometimes, drivers do not know how to install the brake properly because the process could be more complex than the other brake system.  

    How To Install The Electric Brake Controllers: The Step By Step Guide

    To help the electric trailer brake system work effectively, the users should know exactly how to install the brake controller on the tow vehicle and also the way to connect it with the brake system. However, many drivers often have difficulty with the installation. To make it easier, we will share with you some simple steps to do this process successfully.

    Step 1: Disconnect your car battery

    This first step is very important, it can help you avoid injury or damage to other electronic components on the vehicle during installation. You should disconnect the positive battery before doing anything.

    We recommend that anytime when you work with the car electrical device, you should cut off your battery.

    Step 2: Identify the position to mount the brake controller

    You can mount the electric brake controllers in some locations on your trailer. But please note that you should set this device close enough to the plug of trailers. It can help to connect to both the tow and trailer vehicle. The ideal position to attach these controllers is the inside or outside of the drawbar.

    For the other vehicles like: SUVs or trucks, the best place you can mount the controller is below the steering wheel. After determining the location to mount the brake controller, you will drill the holes using a 2-3mm drill.

    electric trailer brake controller

    Step 3: Plug these controllers into the trailer connection

    Using a wiring harness that is specifically designed for your vehicle, connect or plug the controller into the vehicle. One end of the wire plugs into the car’s harness under the dash and the other end plugs into your brake controller. At this stage, you should identify the wire color to connect color-coded wires together.

    Every brake controller that needs to be wired has the same 4 colored wires that each have an important function to be able to activate your trailer brakes . So we’re going to go over what those wires do?

    • Blue wire: This wire runs the length of your vehicle and it hooks up to your seven-way connector on the rear of your vehicle that will send the power straight from the brake controller to the trailer brake.
    • White wire: It can call “ground wire”, you can just ground this to your battery or any existing ground that you have on your vehicle 
    • Red wire (brake switch): It will hook up to the brake switch so when you hit the brake that will signal to the brake controller to send back your trailer brake. 
    • Black wire (Power wire): This wire will connect to the car battery.

    You want to make sure you check what the amperage is needed for each brake controller since all are different so you’ll need to connect that, using a fuse holder or a circuit breaker with the correct amperage so that you don’t ruin the brake controller by giving it too much power. 

    Related: How to Increase Towing Capacity on a Vehicle

    The Bottom Line

    If you own a recreational vehicle or trailer, an electric brake is the best solution to stop both the tow vehicle and trailer safely.

    No matter how fast you are going, it takes a lot of power to slow down the enormous weight of a tow car and its trailer. You need more than the rickshaw’s brakes. So the complete trailer brake is very essential. However, not all drivers know all about the use and usage of this type of brake.

    With the topic “How Electric Trailer Brakes Work”, we hope that our findings will help you have the basic knowledge about the brake trailer system. Do you have any more comments and ideas to share about our article? Leave it in the comments!

    Daniel Jackson
    Daniel Jackson
    Daniel Jackson is the passionate owner and driving force behind RVing Explained. Driven by his own love for the RV lifestyle, Daniel has transformed his personal journey into a valuable resource for fellow travelers. He delves into a wide range of topics, from essential RV maintenance tips to insightful destination guides, all while providing a fresh perspective and a commitment to clear, accessible information. Daniel's content is a must-read for anyone seeking to maximize their RV adventures.


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