If you are towing a heavy trailer without brakes you have little control of that trailer, especially when descending steep grades or during emergency stops. Nothing is scarier than driving down a mountainous grade with a 3,000-lb. trailer following you that does not have working brakes. You suddenly have to slow for traffic ahead, and you feel your trailer swaying violently, pulling your tow vehicle from side to side. Braking harder will only cause more swaying and ultimately a serious accident. The only way to correct the sway is to accelerate quickly to straighten the path of your trailer.
How Electric Brakes Work
The trailer brake wiring harness plugs into the electrical system of the tow vehicle at the tow point, the bumper. This five-point plug serves many functions: running lights, brake lights, turn signals and activates the magnetic brakes. Unlike your tow vehicle, the brakes on your trailer do not activate using hydraulic or brake fluid, rather an electric charge caused magnets to engage the brake drums.
In Cab Brake Controller
A brake control panel is recommended, especially for large travel trailers where extra, finger tip control is desirable. The controller is usually mounted under the driver's side dash and is within easy reach. In that situation of trailer sway while driving down a steep grade, all the driver has to do is apply just enough braking to the trailer by tapping the controller, which will immediately stop all sway.
Electric brakes that come with new trailers typically work well and with few problems, other than minor adjustments, are ever needed. But with age and wear from miles of rough roads and vibration and rubbing, electrical shorts can occur. Wear points of the harness should be inspected at regular intervals and any breaks or cracks repaired immediately. The harness plug can also wear out with time and use, and all connecting should be visually inspected for damage.
Brake Drum Problems
Likely the most overlooked inspection points are the brake drums themselves. Road and weather conditions can cause rust, and the magnets that activate the brakes can freeze in place. Test your brakes by activating fully the brake controller when at a stop, then slowly pull forward. If your brakes are working, they will be locked and the trailer wheels will not roll.
Towing a trailer at highway speeds is inherently dangerous on many levels; trailer sway, wind, rough roads and emergency stops all increase the risk of a serious accident. Pulling small utility-type trailers isn't as risky as their weight is usually under 1,000 pounds. But when the trailer you're towing tips the scales at 1,500 or more, state and federal law requires the towed unit to be equipped with brakes.