Thanks Datto for your reply, I don't think you have read my post above, where i continuity tested my switch that is Not working.
So nope, my light would not have come on at all based on that.
I have tested the wiring circuit to earth which does turn my dash light on. So no probs there.
Switch availability... is my sole reason to come up with a workable solution. When they are all gone, or the last 1 in existance costs $1,000,000.00 then someone can make something work (surely).
Sharing Idea's and experiences to the forum is what this forum is all about. The good, the bad, the ugly.
The internals of the oil pressure switch will be mechanical having a spring inside to close the contacts (single wire earthing circuit) to turn on the light, the energy source will be fluid pressure.
So Instead of using fluid pressure, as there wont be any in this case, and Insert a detent pin into the oriface of the replacement switch (just like the original switch has) efectively has to work the same way.
Admittedly there will be trial and error as to the size of the switch oriface, and detent pin. Possibly have to drill the oriface larger in the switch to accommodate a suitable detent pin, which need not necessarily be steel.
Anyway the theory seams Plauseable to this Mythbusting concept.
Jaso.