[whatsnewell]

FYI, on my coach, the up position, the house batteries provide the power to the relay and in the down position, the chassis batteries provide the power to the relay.

It is in likely in the rear electrical panel. Depending on whether it has been changed or not, it will look like a a round silver can about 2-1/2" tall and an inch in diameter. It is located near the starter relay BUT it is NOT a starter relay in that it MUST be rated for continuous duty. A starter solenoid will burn up after a few minutes when used in this application. Don't ask how I know ;-)

Of course, you know Michael, I have to ask why you know that.....