Buying Guides

How Do Electric Brake Controllers Work?

Ever since man has been hauling things around behind them, they’ve battled with the means to safely and efficiently slow a heavy load down and bring it to a stop. The inertia of a heavy load makes towing, particularly around the pivoting hitch of a caravan or trailer, unpredictable. When discussing how electric brake controllers work, let’s first consider the plight of the humble brakeman.

Brakeman who Manually Applies Brakes
Herbert A. French. / Public domain


A brakeman, or porter, were men that traveled on early trains. Their job was to apply brakes to individual train cars being towed behind a locomotive.

This often involved hanging out of the side of trains and working on top of train cars in all types of weather.

This perilous job often resulted in brakemen falling from trains, colliding with structures on the side of the railway or being run over and crushed.

Brakeman on Vehicle Roof
By Peckwell – “A Picnic,” engraving by Peckwell, published on the cover of The Railroad Conductor, vol. 7, no. 15 (Aug. 1, 1890)., PD-US-expired

Not only that, but the system relied on the brakemen hearing and quickly responding to the driver’s signal or whistle in time to apply the train car’s brakes. This resulted in extra long stopping distances and occasional accidents.

As the ability of trains to go faster improved, so too the requirement for a more efficient braking system. Hence “through brakes” were developed that allowed the driver of the train to be in direct control of applying the brakes to each and every train car being towed.


Fortunately, these days, towing your caravan, trailer or camper behind your vehicle doesn’t require someone hanging off the back of your car. It can all be done electronically.

Towing a Caravan with Brakes
Adapted from
Brakeman, Water Car X1059, Texas and Pacific Railway Company (12801574083)

However, the principle remains the same. You can think of an electric brake controller as your vehicles brakeman. When brakes are activated on the towing vehicle, they signal to apply the brakes on the trailer or caravan as well.

Without proper brake control, the inertia of the load behind can result in excessive stopping distances, damage to vehicle parts as well as danger of shifting loads and jackknifing.


How Electric Brakes Work
Ehsnils / CC BY-SA (

Modern electric brakes on trailers and caravans work by electromagnets and friction. When an electric signal from the vehicle flows through the electric brake controller to the trailer brake, the magnet (5) is attracted to the drum face.

When it makes contact, the drum will cause the actuating arm (4) to rotate which pushes the shoes (3) against the drum, causing friction.

To resist the heat caused by this friction, the shoes are covered in a heat resistant brake pad material.

The degree to which the brake is applied is directly proportional to the current flowing to the electromagnet via the electric brake controller.


There are two main types of electric brake controllers: timed vs proportional.

A time delay brake controller applies the brakes with a preset time and intensity once the brake pedal is depressed. The braking power is not proportional to the pressure you apply to the brake pedal of the tow vehicle. In this way, the trailer or caravan acts as the lead braking mechanism.

This is great for when going off road. The last thing you want is your trailer to be pushing your tow vehicle down the road on a gradient or valley.

However, it relies on the user properly setting the braking power for the road and conditions. Improper settings can cause the trailer wheels to lock or it can cause jerking between the vehicle and the trailer. It can also lead to premature wearing of the brakes over time.

Proportional electric brake controllers, on the other hand, are designed to cause the trailer brakes to be applied in sync with the towing vehicles breaks.

It means the speed of your vehicle and the speed of what you are towing is matched same for same.

Proportional brake controllers usually use an accelerometer to determine the tow vehicle’s rate of deceleration and apply the trailer’s brakes to match. Whilst this creates a smooth breaking experience, it also means the device usually has to be mounted in line with the vehicle direction. So there can be some limits as to where these devices can be installed (with some exceptions, as seen below).

Proportional controllers also tend to be more expensive than time-delayed controllers. However, due to ease of use, they are the most popular of the two types.


Each of the two types of electric brake controllers have their pros and cons. The best one usually comes down to personal preference and what you’re most familiar with. What brake controller do you need? Why settle for one or the other, when you can have both.

REDARC Tow Pro Elite

Enter the REDARC Tow Pro Elite V3, what we think is the best electric brake controller on the market. This model works with both electric brakes and electric / hydraulic brakes, without any adjustments needed.

The Tow Pro Elite gives you the manual, “user controlled mode”, as well as the automatic “proportional mode”.

The small LED lit control knob can be mounted in a switch panel, the side of the steering column, an unused area of the dashboard or the centre console.

On the road, simply leave it on proportional mode, as indicated by the blue LED colour. The dial can be set from 0-10, with zero being no trailer brake applied, to 10 being a maximum of 100% trailer braking power applied. But this will all be proportional to the amount of pressure applied to the brake pedal. There is an initial delay with the trailer brakes coming on, to give a smooth stopping experience.

When going off-road you can tap the control dial twice to set it into user-controlled mode, as indicated by the green LED colour. In this mode, there is no delay with the trailer brakes being applied. They will immediately come on at the intensity the dial is set to.

Electric Brake Controller Dial

In this mode, you’ll want to make sure the dial is set according to road and weather conditions. The aim would be to get the maximum braking power without the trailer wheels locking up. So in wet conditions you would dial down the power a little.

Additional Features of the REDARC Tow Pro Elite

The other benefit of the REDARC Tow Pro Elite is that it has an override feature that allows you to operate the trailer brakes without operating the vehicle brakes. This is done by pressing and holding down the control knob.

This feature is useful if the trailer or caravan starts to jackknife or sway and you need to bring it back into alignment. This option will brake the trailer to a moderate level without applying the vehicle brakes.

Another way in which the Tow Pro Elite is unique is that it has a three-axis accelerometer built in. This means it can be mounted anywhere and in any direction, unlike traditional controllers that needed to be mounted in line with the vehicle direction.

The Tow Pro Elite V3 will automatically calibrate itself based on the mounting position detected, making it a great all round plug and play option.


The installation of the REDARC Tow Pro electric brake controller couldn’t be easier, with the addition of the new Universal Electric Brake Wiring Kits. These are available in three main varieties to suit most vehicles:

1. REDARC Universal Tow-Pro Wiring Kit TPWKIT-013

Universal Brake Controller Wiring Kit

See here for full installation instructions for the TPWKIT-013.

Suitable for:

  • Hilux
  • Fortuner
  • Prado
  • Isuzu
  • Pajero

2. REDARC Universal Tow-Pro Extended Wiring Kit TPWKIT-014

Extended Electric Brake Controller Wiring Kit

See here for full installation instructions of the TPWKIT-014.

Suitable for:

  • Colorado
  • Triton
  • LC200
  • Navara
  • Amarok

3. REDARC Tow Pro Wiring Kit for Ford Ranger & Everest TPWKIT-012

Redarc Electric Brake Controller Wiring Kit for Ford Ranger

See here for full installation instructions of the TPWKIT-012.

Alternatively, you can have your REDARC tow pro installation performed in Perth with AutoElecOz. Simply contact us and we’ll supply everything you need and professionally fit it all for you just the way you like it.


Not only is it safer to use an electric brake controller, but it is also often required by law when carrying loads above certain weight limits. Gross Trailer Mass (GTM) refers to the total weight of everything being towed, including the trailer/caravan and what is inside it. Laws may vary from state to state so be sure to check with the regulations of any areas you’re traveling in.

In Western Australia:

  • Trailers having a single axle and not exceeding 750kg GTM do not require brakes.
  • A GTM over 750kg must have brakes.
  • Trailers with GTM 750kg – 2000kg must have braking on wheels of at least one axle.
  • Trailers with GTM over 2000kg must have braking on all wheels.

In addition, when brakes are in use, the total weight of what is being towed should not exceed:

  • the towing limits specified by the driving vehicles manufacturer.
  • the empty mass of the towing vehicle if the trailer is not fitted with brakes.
  • 1.5 times the mass of the towing vehicle if fitted with brakes.
  • the towing capacity of any component in the vehicle/trailer combination, including the tow-bar and tow-ball.
  • the trailer manufacturers maximum load specifications

For full towing specifications and regulations in WA, see here. When towing your trailer or caravan, be sure to get it weighed at a public weigh bridge when its fully loaded. Steep fines and demerits apply for exceeding your maximum aggregate trailer mass (ATM).


These popular towing vehicles can all have maximum braked towing capacities of up to 3500kgs, depending on model and year:

  • Toyota Land Cruiser 200 Series
  • Ford Ranger
  • Mazda BT-50
  • Toyota Hilux
  • VW Amarok V6
  • Isuzu D-Max
  • Holden Colorado

As you can see, an electric brake controller is an important part of safely towing your caravan, camper or trailer. Not only that but it is a legal requirement when towing above certain weight limits.

Be sure to check out the complete towing range in our online store. Contact us for any support you need, and if in doubt have your electric brake controller professionally fitted for you at our warehouse in Perth.

Safe travels, from all of us here at AutoElecOz.

Related Posts

Leave a Reply

Your email address will not be published. Required fields are marked *