Where is the water pump on a 1999 fleetwood Prowler 39w

Assume you know that water pump typically won't run if your connected to shore water? It operates on pressure differential and the pressure of shore water should keep it from turning on.

With that said - when you say the pump made a noise near the kitchen sink - in some rigs there is a couch/table setup near the kitchen - might take a look under the cushions and see if there is a compartment.