Selection of a Trailer Brake Controller

Understanding the options available for trailer brake controllers, how brake controllers work, and how to determine which brake controller is best suited to your needs are important considerations when installing a trailer brake controller. Even if the vehicle you purchased comes with a factory-installed towing package, you now know that a brake controller unit is still required to operate the brakes on the trailer. How do you determine the best installation?

What is a trailer brake controller? When a driver applies the brakes in the towing vehicle, the trailer brake controller supplies power to the trailer’s braking system. The advent of anti-lock brake systems (ABS) permanently altered the nature of these devices. Once integrated with the hydraulic lines of the tow vehicle’s braking system, brake controllers in the ABS era can now electronically link to that braking system.Do I even need a trailer brake controller? Light-duty trailers typically do not require an independent braking system. However, availability is increasing due to improved safety standards and awareness. Boat trailers, for example, commonly use surge brakes that do not require a controller. Furthermore, the big three automobile manufacturers now include controllers in some of their factory-installed towing packages, so be aware of how your vehicle is equipped. If you do not need one, save the expense.The following is information that you should know about choosing a trailer hitch.Types of trailer brake controllers There are up to four types of control modules depending on how you classify them. The price of trailer brake controllers ranges from $45 to several hundred dollars. If you frequently tow or tow long distances, then an investment in a controller becomes worthwhile.
The time-delayed brake controller is the least expensive and operates by activating the trailer brakes with a prescribed amount of power in discrete time intervals. The operator sets the start delay, power level, and duration of brake application to match the load requirements, how often the vehicle is used for towing, and the operator’s driving style. The controller can be mounted at any angle (you will understand why later). For those who occasionally tow, tow short distances and/or tow medium to light loads, this controller works well.Its primary drawback relates to a lack of variable braking power. In light braking situations, the trailer brakes may become too strong compared to the towing vehicle, causing the trailer brakes to bear the weight of slowing down both the vehicle and the trailer, prematurely wearing out the trailer brakes. Conversely, more forceful braking situations force the towing vehicle to compensate for the limited power provided to the trailer brakes. This condition causes excessive wear (and heating) to the trailer brakes and can result in heavy trailers breaking apart in extreme cases.

Inertia-based brake controller.Classified as a subset of inertia-based controllers, they adjust the trailer’s braking power when changes in the pendulum position are sensed. The harder the vehicle decelerates, the greater the swing it causes, and the more power the trailer brake will provide. The downside of this type of controller is its need for horizontal installation and its potential to be confused by steep inclines.

Proportional controller.Proportional controllers use accelerometers to sense brake intensity and provide proportionally leveled power to the trailer brake. This response allows the towing vehicle and trailer to work together in light, heavy, or sudden braking situations, evenly distributing the brake power needed. The proportional controller’s downside is its cost, which is higher than the other controllers.

Liquid and Electronic Control Systems.Recent innovations have produced hydraulic electronic controllers, which use microcomputers to convert hydraulic pressure into electrical current. As the next generation, they are now the most commonly used controllers in the market, but they are often associated with higher costs—at least until they become more widespread.

Most home mechanics can easily install trailer brake controllers. Newer vehicles typically come with a seven-point wiring harness for installing the controller, but other styles exist as well. If you need to purchase the controller end of the wiring harness, it can be easily found at auto parts stores and online. There may be a factory pre-wire plug hidden below the dashboard. When seated in the driver’s seat, look for it in the location above your right knee. Sometimes, you’ll find it on the left side. If the manufacturer did not pre-wire back to the trailer brake wiring harness, you will need to install it in an unbroken wire. Remember that inertia activation and some proportional controllers must be mounted level to function properly. You should also check the clearance above your knee to prevent the equipment from being crushed while driving.If you are towing under high-demand conditions due to grades, distance, or frequency, you may also consider upgrading the rotors to slotted and cross-drilled types, and the brake pads and brake fluid to high-temperature resistant products.