F250 trailer brake issue

[Fishin]

My 2017 F250 6.7 diesel locks up my boat trailer brakes in reverse, 2025 tuff trailer with surge/disk brakes I checked fuses. The dealer has no ideas. Hooked up to my old man's truck, and the trailer works perfectly. Anyone run into something similar?

 

[scotth]

It’s the wiring in your trailer hitch. For surge brakes you need a fifth wire connected to your reverse lights to disengage your surge brakes

 

[TD10]

If it has the electric lock out. Some have to be pinned.