Will a Brake Controller Stop a Trailer From Rolling Down a Hill into a Tree
Published 06/03/2025
Question:
I installed a brake controller on my tow dolly. It is a dc modulator that controls a voltage 0 to 12 v to trailer blue and white lines. When moving the trailer forward even downhill, the brakes work as expected. When I pushed the trailer backward downhill, the brakes didnt work. My trailer ended up crashing onto a tree that stopped it. My question to you: The electric brakes do not work in reverse? I saw a video in which one of your experts explained electric brakes work in both directions. Please help me figure out about my brakes on 2021 MM 2108DS. Thanks! Liao
asked by: Liao C
Expert Reply:
Hey Liao, yes trailer brakes do work in reverse. I would assume what went wrong had to do with the brake controller more than anything. The brake controller would need power and ground which it was probably getting from your tow vehicle when connected via the trailer wiring but if your trailer was disconnected and able to roll by itself the controller wouldn't have any power to activate the brakes nor would it have anything to tell it to stop if that makes sense.
Product Page this Question was Asked From
Dexter Electric Trailer Brakes - 10" - Left/Right Hand Assemblies - 3.5K
- Trailer Brakes
- Electric Drum Brakes
- Standard Grade
- Manual Adjust
- 10 x 2-1/4 Inch Drum
- 3500 lbs Axle
- 14 Inch Wheel
- 14-1/2 Inch Wheel
- 15 Inch Wheel
- Dexter
more information >
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Liao C.
6/3/2025
Actually, I tested on the voltage while pulling the trailer forward and pushing it backward. I used an external battery to the controller. The trailer battery was not used. When pushing trailer backward on level ground, the brakes worked. It was when I pushed it backward down a slope, the brakes failed to stop it. I hope this gives you more details. Thanks for your time!