Pontoon boat faucet, how do they work?

[Kayakman!]

I have a 2016 StarCraft pontoon with a sink and faucet. We want to get it working. Looks like the water line goes to the back of the back of one of the toons and a bilge type pump sits in the water. Is that to use Lake water to run through the faucet? Also the faucet knob doesn’t turn much at all. How does the system work. How does the pump know when to turn on.
Thanks so much!!!

 

[Scott Danforth]

Should be a fresh water tank, pump, and dash switch.

 

[mr 88]

Pump is pressure activated, stops when it hits xX lbs and when you open the faucet the pressure drops , pump turns on . Follow the water line from the sink to the source

 

[airshot]

Previous owner may have altered the system to use lake water, but originally there should be a fresh water tank with a 12 v pressure pump.