A Mercruiser electric fuel pump only works when you have oil pressure -<br />There is an over ride when starting and you have no oil pressure.<br /><br />What engine - year - make - what do you have ?<br />Will post wiring diagram.
I went back to your PREVIOUS POST for some information on what you are talking about.<br />I assume you order This Pressure Switch.<br />You can either tee into the oil pressure sender with a small pipe tee or there is a seperate pipe plug over the oil filter housing on the block you could use. But you do need to hook it into an oil passage that has pressure for it to work.
Sounds like the switch I have. P goes to pump positive, I goes to ignition wire (purple) for power with oil pressure, and S goes to starter wire from ignition switch or slave solenoid (yellow/red) for power while starting, Mercruiser colors. Mount the switch like Don says.
