Fuel Pump Wiring 96 Mercruiser 4.3

[trbojet]

I just inherited a 96 20' Crownline with a Mercruiser 4.3 LX 6 cylinder. It's in rough shape. Can someone tell me what the wiring should be for the electric fuel pump. I'm getting mixed info. Should the pump run all the time or just when it falls below a certain pressure or only when the starter is engaged? I saw something about oil pressure as well. All of the wires were disconnected from the secondary solenoid on the starter. Thanks.

 

[Scott06]

Runs off the starter during cranking, then from ignition on through an oil pressure switch. If oil pressure is less than 4 psi pump will not run.

Wiring schematic is here http://www.boatfix.com/merc/techbk/96/96hgd4.pdf

 

[trbojet]

Very good information......I had noticed that the fuel pump was staying on, I had also noticed that my oil pressure was reading a high number when the engine was shut down. That makes sense. Sounds like an issue with the oil pressure switch as well. Thank you.

 

[achris]

Oil pressure gauge and the fuel pump oil pressure switch are not in any way related. 2 completely different senders.

And once the power goes off the pressure gauge, the needle can point anywhere. ... these are unsprung gauges so what they read with the power off is complete random, and not a true indication of anything.