Amazing how many suggestions you can receive whn you toss out a question!
If you look at the exploded diagram, you will see that the system uses a motor
to bring in raw water
with a rubber impeller and send that water
to the bowl. A second impeller (metal) that they call a chopper then macerates the waste and sends it on its way. Since both impellers are on the same shaft, raw water
continues to enter the system so long as the motor is engaged.
All too often with this unit, the motor seizes and that is the expensive part to replace. If your motor is functioning as you say it is, then your repair costs are reduced considerably.
There are three hoses. The largest one (1") runs from the base out, which is your discharge line. A second hose runs from the pump housing up to the bowl. The third hose is attached to the pump directly on the opposite side from the hose that runs up to the bowl. This is your intake hose.
Trace the intake hose to its through hull
fitting and verify that the seacock is open. If it is not, you have burned out the rubber impeller and will need to replace it. If it is open, then you have a blockage. Go back to the head and remove the intake hose from the pump housing. Blow air into the hose as the blockage may be in the hose or in the through-hull. If no air flows, then remove the hose from the through hull and first blow air back to the head. If no air, replace the hose. If nor air when you blow air into the through hull, the strainer is clogged. Your need to go swimming or wait until you haul out
. The alternative is to careen the boat if you are adventurous.
Once you have verified the flow of raw water, you still need to replace that impeller. Close the seacock; then empty standing water in the head; disconnect the hose from the pump to the bowl; remove the four ss 1/4x20 bolts that hold the bowl to the base and lift
it off. Ther is a gasket
and it probably reusable. Should take less than 10 minutes.
Now, with access to the base, have some disinfectant and towels handy. Remove the discharge hose and plug
it. Remove the intake hose. Cut the positive and negative wires after you shut the circuit brake. There are four screws that hold the pump to the base. After you remove them, wiggle the pump housing with the motor until it comes loose.
Inside the plastic collar, the chopper/macerator screws off the shaft and then work your way back to what is left of the rubber impeller. Don't remove the impeller housing and you won't have to replace the seal between it and the motor.
kit has the new impeller and seals
The whole disassebly and reassembly should take around an hour, depending upon your constitution.
Oh, if you reverse the positive and negative wires, the motor and pump will run backwards. While the rubber impeller will still work, the centrifigal force for the discharge will not properly function.