Auto Bilge pump fuse

[DesignDay]

The fuse for the auto aft bilge on my 2016 C28 keeps blowing. I'll replace it and it seems to work fine for a period and then it will blow again. I have a 7.5 amp fuse in there, which the diagram shows a 5amp fuse was stock. Any suggestions? Do I need to replace the entire pump?

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[CaspersCruiser]

Turn the manual switch for your aft bilge pump ON to see if it trips the breaker in the manual circuit. If the aft bilge pump is blowing/tripping both manual and auto circuits, then you have either an obstruction in the pump impeller or the pump is bad.

The aft bilge pump on my 2012 R27 is a Johnson cartridge pump. You may have the same one in your boat. It is a pretty simple matter to remove the pump cartridge from the base to check for an obstruction. If there is none, change the cartridge. To do that will require butt splicing some wires unless your installation has blade connectors. I switched to blade connectors when I changed my cartridge.

 

[DesignDay]

The manual switch works fine and the pump functions properly for a few times before the fuse blows.

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[CaspersCruiser]

If the aft bilge pump does not trip the breaker in the wiring of the manual circuit to the pump and the fuse in the auto circuit wiring blows intermittently, then the only thing it could be is an intermittent short in the wiring of the auto circuit.

 

[BB marine]

If you have the original installed bilge pump in a 2016 Cutwater C28 it is a SPX Flow Johnson pump 750 gph. This pump uses 3 amps when operating at max output. The circuit should be protected by a 5 amp fuse. The 16ga wire used to power the pump can handle 10 amp draw, so using the 7.5 amp fuse is still protecting the wire in the circuit. The 7.5 fuse should not be melting if the wiring and the pump are in good working order. My first check would be to make sure there is nothing stuck in the pump. The pump cartridge can be removed to inspect the pump base for debris. If the pump is clear and free of debris then inspect the butt connectors for corrosion. Fluid motion has a reputation for over looking the sealing of the butt connectors. I know my C26 Cutwater had many connections that were not heated to seal them. Corroded connections increase resistance, increasing heat and increasing amp draw. If the connections are clean and corrosion free then it is time to think about replacing the pump.

 

[DesignDay]

I pulled the pump and checked all the butt connectors and everything seemed fine. I removed the cartridge and the blade and think i found the culprit. the shaft was pretty well clogged and wrapped with dog hair! I tested the auto run maybe 20 times with my fingers and no fuse blown. My dog loves the boat too much to keep him off of it so I think i just found a regular maintenance item for me.