where is the waterpump ona daihatsu hijetta camper ?

hi I have just bought a P reg Daihatsu hijetta camper, I was told everything was working, but I cant get the water to come out of the tap, when I press the pump button next to the tap nothing happens, it has its own inlet to fill the water tank on the outside, this is full, the previous owner said it runs of the leasure battery, I cant see any separate switch , any ideas ?
thanks

I would guess it's in/on the tank if it is electric. Is it a foot switch? If it is have you tried pumping it incase it is a manual jobbie have seen these in caravans don't know whats fitted to a Hijetta.