Big Trailer Rentals

How to Use a Trailer Brake Controller

This guide will show you how to properly use a trailer brake controller while pulling a trailer. 

How Do I Know If I Need a Brake Controller?

If you are trying to decide if you need a brake controller to pull a trailer, the short answer is, yes.  The way you will know for sure is if the trailer you are towing has brakes, then you need a brake controller.  If your trailer has brakes, but your towing vehicle does not have a brake controller, you will not have any ability to apply the trailer brakes.  

How Do I Know If My Trailer Has Brakes?

The easiest way to find out if a trailer has electric brakes is to safely crawl under the trailer and look.  First, block the tires using wheel chocks.  Bring a flashlight with you and crawl under the trailer.  Look at the inner side of the wheel.  If you see two wires running from the frame of the trailer and feeding inside a hole in the backing plate behind the wheel, the trailer has brakes.  Every wheel that has these wires will have brakes.  You may not have brakes on all wheels, depending on how the trailer was designed at the manufacture.  However, remember that having brakes on a trailer does not mean the brakes actually work.  

How Do I Know If My Truck Has a Brake Controller?

Trailer Brake Controller

Most trucks come with a brake controller installed by the manufacture (OEM).

The brake controller usually has an image of a trailer and you would see a dial and two small knobs. 

On the OEM controller, the brake settings are usually controlled from the dash but the settings are displayed on the screen directly on your instrument panel.  Aftermarket  brake controllers look similar, but are often installed under your steering column and have a digital readout directly on the controller module.

Types of Brake Controllers

The two most commonly used trailer braking systems are Time Delay Brakes and Inertia Brakes.  Inertia brakes use an accelerometer to detect changes in momentum.  The trailer brakes are applied based on these momentum changes.  The Time Delay Brakes are activated when the driver presses on the brake peddle.  The Time Delay Brakes are more common on most trailers and this is the braking system we will talk about in this guide. If you need to purchase an aftermarket trailer brake controller, you can find them at your local parts stores or they can be purchased online.  There are several brands but Curt and Reese are among the more popular brands.

Follow These Basic Steps When Using a Brake Controller

  1. Connect Trailer:  Be sure to connect the light plug.  The plug will be 4 pin or 7 pin, but most are 7 pin which is a round plug.  This plug will supply lights and brakes to the trailer.  If you have an OEM brake brake controller, your display screen will most likely detect and indicate that the trailer is connected. 
  2. Adjust Settings. Your controller should have a plus and a minus button or a dial that controls your braking force also known as "Gain."   For OEM controllers that are built into your dash, your settings will most likely appear on your digital display screen in your instrument panel.  Aftermarket controllers will display the brake setting number right on the controller.   The brake controller typically displays a number of "0-10."  This number is the amount of braking force or gain that will be applied to the trailer brakes.  The higher the number, the more braking power.
  3. Test Brakes. Begin driving about 25 miles MPH on flat level ground. Apply the brakes as you normally would when coming to a stop. If you don't feel enough braking force, increase the number on your gain until you feel that you have adequate braking to stop safely. If you have too much braking force, reduce the number on your brake controller until you feel you can stop safely. Trailer brakes are intended to help the towing vehicle and trailer come to a smooth stop. The trailer brakes should never replace the braking ability on your towing vehicle. Your towing vehicle has it's own set of brakes.
  4. Check Mirrors and Tires:  If you are driving on a paved road, glance in your mirrors as you apply the brakes.  If you see smoke in the area of the tires while applying the brakes, your gain is set too high and you are causing damage to your tires.   After you have come to a safe stop and you have parked, examine your trailer tires.  If you see flat spots on your tires, there is too much brake force being applied to the wheel and you should reduce your gain. 
  5. Loading and Unloading:  Every time after loading, unloading, or changing the amount of weight loaded on a trailer, you will need to adjust the "gain" setting on your brake controller. With more weight, you will need more gain. With less weight, you can reduce your gain. 
  6. Avoid Damages:  If the trailer brakes are not set properly, the tires and brakes on a trailer can be damaged and you could lose some or all braking ability.  This is not only unsafe, but it can amount to thousands of dollars in repairs.  


Disclaimer: The information contained on this page is provided by Big Trailer Rentals, LLC as a general guide to assist with the proper use of a trailer brake controller.  Each brake controller and trailer is different.  Always follow the instructions from the manufacture for the specific brake controller you are using.   Big Trailer Rentals, LLC is in no way liable for use or implementation of information provided in this guide.  


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