[richeyb]

I had an older Keystone Sprinter with the same water hookup ports as yours. As Jimcol said put you hose in the capped port to the left and when it over flows it is full. You can then Turn on the pump and it should operate on demand when you turn on your faucet. I have occasionally had my pump trap air and not pump, in that case I had to prime it by hooking a short piece of hose to the in side port of the pump and fill it with water. And then re-hook up the “in hose” and try the pump again. No such problems with the newer models.