Low Oil Switch

"I have twin 360 Chrysler'

"I have twin 360 Chrysler's with factory electronic ignition and single station controls. I noticed a 2nd oil pressure sensor which appears to be only a low pressure switch. The switch appears to be open even under normal oil pressure. Does anyone know where this switch goes and if it is closed or open at low pressure? I have never heard a low pressure buzzer in the boat, but it might be due to these bad sensors. The oil pressure gauge senders work fine so it is not a plumbing problem. I see a shiny metal box under the black plastic electronic ignition cover mounted to the circuit breaker support piece immediately behind the starter solenoid. Perhaps this is supposed to be a buzzer? Neither of these items show up on my schematics for the 1976 engine."

That is the oil pressure switc

That is the oil pressure switch that closes to provide 12V to the voltage regulator for the field wire on the older three wire alternators.
No oil pressure - switch open
oil pressure- switch closed.
It prevented the alternator from energizing during starting
It can be removed when a internally regulated alternator is installed.
Joe

"Thanks Joe... That's one

"Thanks Joe... That's one I would never have thought of. I guess I will be going through a few batteries if I don't replace them both. I assume the signal goes from the hot side of the ballast resistor, through the oil pressure switch and then to the small voltage regulator mounted opposite the starter solenoid?"

Sometimes that switch is used

Sometimes that switch is used to operate the low oil pressure alarm. Has your boat got one?

Jeff

"Jeff,
No it does not have a

"Jeff,
No it does not have a low pressure alarm. I found actual schematics under the black plastic covers that protect the ignition parts. Between the two engines I was able to decipher one schematic. I redrew the schematic and made an 11 x 17 pdf. It is 1976 Chrysler 360's with factory electronic ignition. I tried to upload but it is too big, so if anyone needs it, please let me know and I can email it."