I trained with a young lady who was convinced the engine brake was to be used only when the truck was stopped. Engine break.. Let the poor thing rest. Give it a break.. See?
Remember on the early 70s KW conventional a dash switch with Trailer Hot Line on it?
On our trucks it wasn't hooked to anything but we told the greenhorns never to touch it because it activated an explosive charge that would blow the pintil hitch and release the trailer in case of a fire.