[Chester Stone]

I am installing Air Force One braking system for my towed Honda. Their special Coach Air Tank Assembly is installed in the coach and I am locating it at the back just above the engine electrical panel. I need two sources of coach air, Supply Air (unmetered) and Metered Air. My coach has two air connections on the rear bumper, and the metered air is on the drivers side and was used to supply air to my old system. I assumed the connector on the curb side was unmetered air, but there seems to be no air supply there. Can someone give me information on the curb side air connection?