Fuel pump question

[slow96z]

I have a 98 Starcraft Starship Aurora with a Mercruiser 260 in it. The fuel pump seems to be tied into the ignition circuit and gets power whenever the key is in the on position. This is fine for running but it spins the fuel pump continuously even when the engine is off. I know in cars the fuel pump spins until primed and then it shuts down but this one doesn't stop. It is my understanding that in boats the power to the fuel pump is supposed to come from the starter circuit for start up and then from the oil pressure switch for running, but in this boat that is not how it is set up. I looked at the wiring and it doesn't appear that any of the factory harnesses near the fuel pump have been altered so it appears it was this way from the factory, does anybody know if that is the case? Should the pump run all the time? Should it eventually turn off? I have no problem running a new power wire to the fuel pump from the starter and oil pressure switch, but do I need to?

Please help me out here, I know way more about cars than I do boats!

 

[Don S]

Re: Fuel pump question

Something is wrong, and no, it didn't come from the factory that way.
The only times the fuel pump should run is with the starter engaged, or with the engine running and power coming from the oil pressure switch. Something is wired way wrong.

Look at the starter solenoid on top of the starter, is the purple/yellow wire on the small outside terminal? Is the batter cable touching the small terminal?

Maybe this drawing will help you.

 

[slow96z]

Re: Fuel pump question

Thanks for the diagram Don. I traced out the wiring and found that the wires were correct on the starter but the oil pressure switch was bad. Replaced it and everything is working as it should.