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How to Adjust the Trailer Brake Controller? An Expert’s Guide

Fact checked by Ronal Dowens


When you decide to hook up a travel trailer to your car or truck, you will find that coasting to a stop, which is one of the most routine things to do while driving, becomes quite difficult because of all the weight behind you.

Fortunately, your trailer also happens to have a nifty brake controller. However, you need to learn how to adjust the trailer brake controller for it to work perfectly.

What Does a Trailer Brake Controller Do?


When you step on the brakes, your tires will start screeching before it comes to a stop if you were to simply hook up your trailer to your towing vehicle. This is because the trailer did not know that it needed to apply its brakes too. This often causes serious accidents, leading to the trailer and the towing vehicle toppling over.

A brake controller prevents this from happening by telling the trailer when you are stepping on the brakes. It also tells you how much braking pressure it needs to provide so both the towing vehicle and the trailer will be able to stop without any issues.

Different Types of Trailer Brake Controllers

There are two distinct groups of brake controllers, and we will be discussing both of them in detail. These are:

Proportional brake controllers – These brake controllers make use of a motion detector to find out the rate at which the tow vehicle is stopping. The very moment that you step on the brakes, the proportional brake controller applies the same amount of braking power on the trailer’s brakes.

For instance, if the towing vehicle stops abruptly, the trailer will do so too. If the tow vehicle is slowly coasting to a stop, the brake controller will make sure that the trailer does the same thing. Because both the towing vehicle and the trailer are applying the same amount of braking power, the amount of wear that both braking systems receive will be minimal.

Time delay brake controllers – This trailer brake controller provides an already pre-set amount of braking power on the trailer’s brakes. The driver of the tow vehicle adjusts the time delay controllers beforehand depending on the perceived road conditions ahead.

As the name suggests, there will be a bit of a delay between the time when the driver steps on the brakes of the tow vehicle and when the brake controller turns on the brakes of the trailer.

Which Type of Brake Controller is the Best?


If you have enough room in your travel trailer budget, you should get the proportional brake controller. Be warned though, this type of brake controller is quite expensive, hard to install, and also expensive to fix when it breaks down.

Time delay brake controllers are the more popular choices because they are cheaper, and easier to install and maintain. The issue with the time delay is that between stepping on the brake pedal and the trailer brakes, engaging can be dealt with using a sync switch.

This specialized component allows the driver to adjust the length of the delay. With proper tuning, the time delay will be quite negligible.

Installing the Trailer Brake Controller

For convenience’s sake, let’s assume that you chose the time delay brake controller, which is fairly easy to install. The first step is to mount the controller in a place that is easy to access. The most common installation point is under the dashboard and just above the driver’s right leg.

Mounting the controller this way makes it easier to monitor the controller and react immediately if any problems arise. To install the brake controllers, you need to attach the correct wires in the correct place. There are four wires that you need to connect correctly, namely:

  • Trailer feed – This is the cable that provides the braking power to the trailer connector.
  • Ground wire – This connects the brake controller to a negative, grounded source, thereby preventing the brake controller from short-circuiting.
  • Brake switch – This is the wire that transfers power to the brakes once the driver steps on the brake pedal of the towing vehicle.
  • Batteries – This provides power to the brake controller.

Although brake controller kits are relatively easy to install, you can still have a professional electrician handle the job if you are uncomfortable handling bundles of electrical wires.

On the other hand, if you know what you are doing and you can follow the instructions regarding controller installation then you can DIY it. Properly installed, brake controllers will work properly.

How to Adjust Trailer Brake Controllers Properly


When set properly, the brake controller will pair up the tow vehicle. It will be as if the two components are braking by themselves. If you fail to put enough power on the trailer brakes, it will be up to the towing vehicle to slow down and eventually stop the trailer.

Don’t put too much power – Too much power on the brakes and the trailer will be prematurely stopping the trailer, causing the towing vehicle to whiplash. Any of these mistakes can cause the braking systems of both the towing vehicle and the trailer to prematurely wear down.

The bottom line here is that you need to set the brake controller properly for the job at hand.

Change settings when switching trailers – For some trailer users, this means that they will be making the initial settings and then tweaking them ever so slightly until they achieve “towing perfection”. However, if you use your vehicle to tow different trailers then you will be making adjustments every time you switch. You will need to take into consideration the weight of the new trailer when making adjustments.

This is a problem that drivers hauling horse trailers have to do regularly. It is because there will be days when they will be hauling one horse in the trailer, pulling two, and they also need to carry an empty trailer, also known as “deadheading”.

Check the manual for detailed instructions – Depending on your choice of brake controllers, it might need different approaches regarding the settings. You should consult the manufacturer’s instruction manual for detailed instructions on how to adjust the trailer brakes controller.

If you do not have the manual on you or you lost it, you can just go to the manufacturer’s website and download a PDF file of the manual. If your brake controller is older than the internet, and you cannot find the right instruction manual for it, then it is probably time to get a new brake controller, something that is a bit up to date perhaps?

General Tips for Adjusting Electric Trailer Brake Controllers

You need to take the temperature of the brakes into consideration before making adjustments to the brake controller settings. You will need to heat your brakes a bit before you make any settings to the brake controller.

To do this, pull up the manual brake lever on the brake controller while you are driving down the road at around 25mph. Since you will need to engage the brakes at the trailer side, bring along a companion to pull on the brakes for you.

This method is not for beginners because if you put too much force on the brakes, they lock up and cause a huge mess inside the trailer. It is best to check your brakes first in the safety of your driveway while rolling at 5 miles per hour. The objective here is to find the power setting that will slow down the rig considerably without locking up the brakes.

If you do not have a driveway that is long enough, it is recommended to look for an empty parking lot where you can do your adjustments in peace. If possible, look for a gravel-lined parking lot because you will get more feedback to make adjustments easier.

For instance, you will hear your wheels scrape off the gravel when your brakes lock up. This means you have to dial down the braking power quite a bit until you no longer hear the trailer wheels locking up.

Once you know the correct settings for gravel, you can use that as the base level for when you are fine-tuning the brake controller for use on pavements.


You should never hitch up and pull a travel trailer behind your vehicle. For one thing, doing so will mess up the brakes of your vehicle quite a lot. That is because the trailer will not be applying its brakes. The one responsible for stopping both the trailer and the towing vehicle will be the towing vehicle only.

This practice can lead to serious and expensive brake damage. To make towing your travel trailer a whole lot safer, you should get a trailer brake controller as soon as you can. This nifty little gadget will allow you to control the brakes of the trailer, making sure that it will also apply the brakes at the same time you step on the brake pedal in the tow vehicle.

However, to make it even more effective, you need to learn how to adjust the trailer brake controller so that the trailer will not fishtail out of control. This can also prevent causing a huge amount of damage to your braking system.

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