Noisy Powertrac Brake Controller, Part # 39523 on 2008 Nissan Frontier

Expert Reply:

It is not unusual for time-delayed type brake controllers to make a slight humming or buzzing noise, but if what you are experiencing is louder than that, it points to either a fault within the controller itself (such as a relay) or a wiring issue. A pulse preventer will not help your particular issue. Carefully check all connections, making sure there are no loose connections, especially on the connection leading to the leading to the brake stoplight switch (if the controller was hardwired). If a wiring adapter was used, make sure that it is securely seated in the connector and that all of the wires leading to the plug are tightly in place. Make sure that the trailer connector is grounded properly. The Pulse Preventer is not necessary for vehicles that have a different bulb for the stop and turn signals (amber turn signals). You do not mention the age of the brake controller. If it is older than your vehicle, it might need replacing. As with any electronic component, brake controllers have a limited lifespan.

expert reply by: Mike L