Trailer Brakes Make Buzzing Sound when 7-Way is Hooked up to Tow Vehicle

Question:

I purchased a new 7pin trailer wire/junction box from you guys a couple of months ago. When I hooked it up, the brakes on my trailer, Dexter 3.5K make a buzzing sound. Did I do something wrong?

asked by: Jeff D

Expert Reply:

Sometimes you can hear a slight buzzing sound when you hook up your 7-Way but not always. This may be the case in your situation.

Typically when people hear the buzzing noise is when the brakes are engaged. If you are not applying the brake pedal in your tow vehicle but your trailer brakes are engaged then you most likely crossed the 12V power wire with the Brake Controller wire, or they are touching in the Junction Box # 38656. This will immediately apply your brakes to full force.

If, however, you hear a slight hum but your trailer brakes are not applied then you have nothing to worry about.

If your trailer brakes are locking up just let me know and I can help you further troubleshoot.

expert reply by: Jon G

Xavier

4/18/2024

What if I get a humming sound from the brake controller inside the cab of the truck when applying the brakes only? Either pushing the brake pedal or manually engaging

Jon G.

4/22/2024

@Xavier Brake controllers typically shouldn't be making any noise when they are being used. I recommend reaching out to the manufacturer to check and see if that's normal or not. If it's a brand we carry just let me know which controller model you have and I'd be happy to reach out to my contact for you!