[Fulltiming]

Everything that uses air. It is a replacement for the engine mounted air compressor when you are stopped. In your case, no much other than filling the airbags when you don't want to start the engine, possibly extending the generator, possibly an air ride seat. Newer coaches would operate the air toilets, the interior and later entry doors, the step cover, and in some coaches, a slide out tray for a freezer or entertainment center and the air operated dump valves.