Phillip,
In your other comment, you said "Brake has locked three times in the last two years" did it apply while the coach was moving? Or, it would not release when you took it out of park? If it applied while driving I would encourage replacement. Otherwise if it has not applied while driving, and holds when you give it throttle with the engine running, coach in drive, and the yellow push/pull button out, then there is no need to replace it.
Phillip,
On the 14 pin connector at the controller, with key on, power should be found on pins 1 and 10, and ground on pin 14 for the 12vdc supply.