There are almost always other plugs into the oil galley
so you can separate the switch from the sender, however if I could source the OEM part unless It was crazy expensive that is what I would do, switches come either normally open or normally closed, odds are yours is normally closed, senders however can have different resistance values, so you need to know the correct value to order one.
If its working I’d leave it alone, but order a spare, it may be hard to source off the beaten path. You may also measure the resistance of the sending unit and determine for certain that the switch is a normally closed one, and write both down in your engine
log in the event that you had order another one, and your senders may be BSP thread too and not NPT, BSP can also be harder to find.
On edit, it’s also common for switches and sending units to have a very small hole that senses oil pressure, this is so that if the housing ever gets busted there won’t be a major oil leak
, but a slow one. However a lot of “bad” switches and senders aren’t bad, just the hole is plugged and carb cleaner will often clean that hole out, just don’t get any in your eyes.
Years ago we had a Ford truck diesel
that the hole would plug
and set the low pressure alarm off, and that was a combo unit too, so you got got a low light and the pressure gauge reading zero, which scared me the first time it happened and stranded me, cause of course you always back up the light with the gauge and if both are low, that validates you really have no oil pressure.
However is it possible that sending unit is meant to drive two pressure gauges as in a separate helm
? Pratt & Whitney Turbine’s do that if you have a dual cockpit
aircraft and two gauges. Just wondering.