Customs electric fuel pump

I want to add an electric fuel pump to one of my collector cars. But I also want to do it safely and have a cut off switch in case of low oil pressure, accident, etc. If I use an oil pressure switch as a ground for the fuel pump, I'm guessing I'd want one that is "NO" normally open but would close when oil pressure is present....do I have this straight? Does anyone know of a source for this type of safety switch? I believe the ones commonly used for oil pressure warning lights are NC normally closed which would be the opposite of what I want, correct? Any suggestions are most appreciated..thanks..lance

 

You could probably tee in a NO switch
Not a bad idea, experiment with it


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Just a guess here. I would think the ones for idiot lights are NO and then close to turn on the light. You would want one NC and then open to shut off the pump.

 

For an electrical load such as an electric fuel pump it would be best to use the pressure switch to activate a relay to power the pump.

 

https://www.partsgeek.com/wj27yvt-c...and-engine-oil-pressure-indicator-switch.html

 

Here's one way to do it: https://carterfuelsystems.com/resources/safety-interlock-system-installation-instructions

I like to use a relay powered up from the pressure switch. I just use a normally open pressure switch that closes under oil pressure and switches to ground, energizing the relay (the other side of the relay coil is wired to positive). I run a wire from the pressure switch to a momentary toggle switch (that also switches to ground), for use as a manual prime/override. Using the ground to activate the relay keeps positive wires to and from the engine at a minimum, making things a bit safer.

 

you could use a Standard Motor Products PS-64, and wire the S terminal to the starter wire, and the I terminal to the ignition, and the P terminal to the pump. then when starting the engine, it will run the pump, when the engine is running, it will run the pump, when the engine quits but the ignition is on, the pump will stop.

I've been using this setup for a couple decades, seems to work. With a normal pump that draws less than 5 amps, no relay is necessary.

 

Could you also consider one of these inertia switches?