Brake Controller/Trailer Brakes UPDATE Question

Hmm, when I used to manually engage my TT brakes then try to move forward, the resistance was unmistakeable. Period. On a really stubborn job in order to save time sometimes I connected a 12 volt source at the trailer brakes and worked backward to the tow vehicle.

And here I always thought trailer brake lights were part of the automotive brake light system because of turn signals and none of that had anything to do whatsoever with the trailer electric brakes or wiring or connector pin.