I think Peggie has covered it but I'll put in my 2 cents.
Because your intake pump and discharge pump both run on the same motor
, clean water
should be coming in from the rim of the bowl at the same time black water
is going out the bottom of the bowl. Hold the flush button long enough for all of the black water to go overboard
or into your tank. This will help prevent build up in the hose and smell permeating the hose.
For your current
problem, no water coming in, first make sure the seacock is open.
If it is open start looking for blockages in the intake.
Remove the hose from the intake pump on the toilet. Check that it is clear.
If you can get it below the waterline, water should flow from it.
If water doesn't flow, remove the hose from the seacock. Water should flow freely into the boat. If it does, the hose is blocked. If it doesn't the seacock is blocked.
If water is getting to the pump, it's time to remove the pump and inspect the impeller.
By now you should have found the problem. If you haven't, the pump is probably worn out. This is very unlikely.
This is the replacement pump assembly. Jabsco 37041-0010 Toilet Motor / Pump Assembly 12 v.
It is very unlikely you'll need this as long as the motor
Since the boat is new to you, my bet would be on a closed seacock.