Brakes for trailers

A brake controller is usually an oem or aftermarket installed device or module. It is mounted to the tow vehicle's drivers side dashboard area that engages a trailer's braking system time delayed or proportional to the tow vehicle's brake engagement when slowing down or coming to a halt. A brake controller is not needed with a trailer surge braking system unless using modern electric over hydraulic devices.Most basic brake controllers will generally have a +/- gain adjustment. The tow vehicle operator would set the gain as high as possible but without the trailer brakes locking-up after making a few test stops. The heavier the trailer, the higher the gain adjustment would be set and therefore the less chances of wheel lock-up.