I have a 1997 3500 Express Cruiser w/ twin 8.3 Cummins. When commissioned after the winter, the FloJet water pump under the floor, in front of the front V-berth, does not have 12V power going to it, and therefore I have no domestic running water in the boat. The “water” breaker in the breaker panel is on and lit, indicating 12V. Is there some sort of safety, inline fuse, or something that could disrupt the 12V getting from the breaker to the pump? Also, what is the reasoning behind the second FloJet pump?? That particular pump never seems to run at all.
I have a 2000 41 open. Only thing i can suggest on the power issue is to trace the wiring. Make sure youare getting power through the breaker first. Then meter the wires at the pump. There are 2 red wires at the pump. One coming in to the pressure switch and one going from the pressure switch to the motor itself. See if there is power at the switch.
The reason for 2 pumps is to keep up flow and pressure. Mine has 2 and both run at the same time. My pressure is good even if I am in the shower and someone turns on a faucet, you don't notice.