most people dont understand the newer trailers actually use a hydraulic actuator that runs electric brakes on thier trailer wheels

if you have a 5 pin trailer plug, that extra wire is what send the signal to the electronics to keep the trailer from juicing the brakes when backing up... once the actuator is pushed down, it applies more current to the brakes meaning more braking force..... so in reality you wouldnt back up very easy if the current wasnt cut off

my point being- a LOT of newer trailers already have the electric brakes being submerged in the water
