Cabin water pump is sending water gushing out fresh water inlet at the post and not thru the cabin faucets. Pump is working but sending water out the inlet.
some folks warn that what I'm about to tell you will break the inlet.> Well. it's broken already so what do you have to lose? (A dry shirt)
Remove the screen washer (Get a new one at the hardware as it likely can stand to be replaced. or reuse it)
There is a little usually white "Button" behind it. With water pump on push button You will get wet IF something is jamming the valve it may flow out. Or not