oil pressure alarm

[Cliff]

After a nearby lightening strike the oil pressure alarm would not go off when engine was started. So, i ran the engine a bit to see if it would overheat which it did not but when i tried to restart it, nothing happened. I figured i seized the engine. When i started it the next day, again alarm did not go off. This time i turned the engine right off. Any thoughts? Thanks

[jentine]

Does the engine have oil pressure?  Is the alarm working?  My intuition is that the alarm was damaged by the lightning strike.  Electronics are very sensitive to electrical surges.  Diesel engine oil pumps are not.

[Cliff]

I did not apply a pressure meter but the engine ran cool altho next time i went to start if, nada!  The next day it started fine but alarm would still not go off. It is now my view that you are correct and that the alarm was fused in the open position. I am replacing it and we will see what happens. Thanks

[sselinger]

I has a similiar problem on my Catalina 27. The oil presure alarm uses  a reverse biased diode as a switch to activate the alarm. The close by lightning strike induced enough voltage in the circuit to blow the diode. The problem was not the switch on the engine, but the diode in the busser assembly.

PS be glad you weren't the boat that took the direct hit. It cost my neighber $12000 in repairs.

Steve Selinger
Aquila #1047