Oil Pressure Switch

[Quarterwave]

Hi everyone,

I recently bought a new oil pressure switch, which I'm using as part of a switch from a mechanical fuel pump to an electric fuel pump.

Please see the pic for reference.

The gold-colored switch that is on the left is the new one and the black-colored one of the right is the old one.

As the new one looks totally different, is it still ok to use?

 

[harringtondav]

Both are your oil pressure gage switch, and assuming they put out the same resistance range, it should be OK, but has nothing to do with an electric fuel pump. The two terminal switch is your low oil cut out switch. It should be open at engine off, closed w/oil pressure, It needs to be wired in series with your elec. fuel pump. This will shut off the fuel pump at engine kill or stall, and kill the engine at zero oil pressure by shutting off fuel.

 

[Bt Doctur]

Both are your oil pressure gage SENDER, not switch . In the first pic the unit with the 3 blades is the fuel pressure switch. It has 3 connection 1 gets 12 volts from a switched source, 1 goes to the starters outer most post for power during cranking, the last goes to the pumps wiring

 

[Bt Doctur]

 

[Quarterwave]

Thanks everyone. I didn't have the wiring schematic from the factory service manual in front of me before I posted. Apologies!

 

[Fun Times]

The gold-colored switch that is on the left is the new one and the black-colored one of the right is the old one.

As the new one looks totally different, is it still ok to use?

The black one on the right is for your oil PSI gauge at the helm.....The new gold colored circled in red is normally used as a switch to sound the warning horn or change status of a red oil light......The chrome above the gold is for the fuel pump switch.

https://www.ebay.com/sch/i.html?_fr...acat=0&LH_TitleDesc=0&_osacat=0&_odkw=3857532
https://www.ebay.com/itm/OEM-Mercru...ender-Sensor-Switch-87-805605A1-/142233195668

OIL PRESSURE SWITCH

Brand: Indmar SKU: IND-645006
https://www.marinepartssource.com/o...MIrb696vmm3AIVxY-zCh0PyQI5EAQYAyABEgJu9PD_BwE

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[harringtondav]

Both are your oil pressure gage SENDER, not switch . In the first pic the unit with the 3 blades is the fuel pressure switch. It has 3 connection 1 gets 12 volts from a switched source, 1 goes to the starters outer most post for power during cranking, the last goes to the pumps wiring

Semantics. Whatever. Where I was book learned, any device controlling electrical current, thus voltage, was called a switch. But I'll remember to go with the flow to avoid disagreement.

 

[bruceb58]

Semantics. Whatever. Where I was book learned, any device controlling electrical current, thus voltage, was called a switch. But I'll remember to go with the flow to avoid disagreement.

A sender is different than a switch. A sender has variable resistance caused by the oil pressure. It's just a variable resistor....not a switch.

 

[harringtondav]

A sender is different than a switch. A sender has variable resistance caused by the oil pressure. It's just a variable resistor....not a switch.

I just installed one of these. The description might help explain my confusion. https://www.wholesalemarine.com/moeller-reed-switch-fuel-sending-unit-79135.html

 

[bruceb58]

I just installed one of these. The description might help explain my confusion. https://www.********************/moeller-reed-switch-fuel-sending-unit-79135.html

I know what you were trying to post. Reed switches are just magnetic switches. For a fuel sending unit, you just have a whole bunch of reed switches along that shaft and the float has a magnet that energizes the one it is next to. Completely different than a resistive oil pressure sender.