engine alarm won't shut off

[Toby1979]

2001 Beneteau 473 with a Westerbeke 71C-four installed
Engine starts normally but the oil Pressure / water temp alarm doesn't silence when the pre-heat button is released
Engine is cold. It starts right up. The oil pressure comes up to 50-60 psi
Releasing the pre-heat button as soon as it fires doesn't kill the engine like it used to
Unplugging the oil pressure switch or the water temp switch has no effect on either the alarm of the engine running
I have cleaned all the contacts and connectors on the engine the 10 amp breaker tested good

Any clues at anything I missed

 

[capta]

2001 Beneteau 473 with a Westerbeke 71C-four installed
Engine starts normally but the oil Pressure / water temp alarm doesn't silence when the pre-heat button is released
Engine is cold. It starts right up. The oil pressure comes up to 50-60 psi
Releasing the pre-heat button as soon as it fires doesn't kill the engine like it used to
Unplugging the oil pressure switch or the water temp switch has no effect on either the alarm of the engine running
I have cleaned all the contacts and connectors on the engine the 10 amp breaker tested good

Any clues at anything I missed

"Releasing the pre-heat button as soon as it fires doesn't kill the engine like it used to", is a good thing, no?
Normally, when you release the preheat button and start the engine, the alarm won't go off until you have oil pressure in the engine. If it continues, I'd not run the engine for any length of time until you identify the problem. It could be the neutral start switch, a bad oil or water temp sensor/sender or a short in the wiring. It should have nothing to do with the preheat button.

 

[Toby1979]

holding the pre-heat button by-passes the oil pressure switch on the engine until the oil pressure is up The function of the oil pressure switch on the engine to shut down the engine if you lose oil pressure, before the engine destroys itself

 

[Davidasailor26]

The function of the oil pressure switch on the engine to shut down the engine if you lose oil pressure, before the engine destroys itself

That’s unlike most engines. Usually the alarm is just an alarm. There are also usually lights for over temp, oil pressure, and charging failure. Do you have those lights and do any of them illuminate?

 

[JoeWhite]

You may have a bad oil pressure switch. While engine is running, unplug the two wires from the pressure switch and connect them to each other. If the alarm stops then bad switch. Also unplug the high temperature sensor switch wire. If the alarm stops then bad sensor. If these tests failed you will have to look at the wiring diagram.