Breakaway Switch Melted/Burnt

Just to add a little more to this topic ...
I was backing my 5th wheel into a tight spot and making some sharp
turns, and either my breakaway switch plug fell out or the wire got
caught on the hitch, which pulled the plug. Either way, we soon
noticed smoke coming from behind the trailer tires. I crawled under
and saw that the insulation on the wires running to the brake on the
front trailer tire was melted and the wires were shorting together.
I crawled out from underneath the trailer, hurried to the TV and
quickly disconnected the trailer cable. At that point, I noticed
that the breakaway switch wires were also smoking/melting and the
switch was melting. I then ran to the trailer, fumbled for my keys,
and unlocked the battery door and disconnect the trailer battery.
That stopped the immediate problem, but now I had others. I had to
be towed to a repair shop that could fix and inspect the brake wires
(including the wires to the magnets inside the hubs), and replace the
breakaway switch. My month-old RV batteries also now seem to be shot
since they will not keep a charge and the electrolyte measures
nothing on a hydrometer. All of this is just to point out that
a pulled pin on a breakaway switch can cause a lot of serious
problems.

In reading this forum entry, I now have a question that is puzzling me. Since the trailer brakes do not engage unless the trailer is moving (i.e. the wheels/drums are rotating), how does the manual override on my brake controller set the trailer brakes when I am hitching/unhitching and the trailer is stationary?

jerdew wrote:
In reading this forum entry, I now have a question that is puzzling me. Since the trailer brakes do not engage unless the trailer is moving (i.e. the wheels/drums are rotating), how does the manual override on my brake controller set the trailer brakes when I am hitching/unhitching and the trailer is stationary?

The magnet will stick to the drum face anytime juice is applied. When this happens and "if" the drum rotates (even a few inches or less) the shoes will deploy and lock up the brakes.