I must admit I'm fairly unfamiliar with dry sump and what the warning light should indicate so, few questions...

Is oil pressure related to oil quantity of oil in the engine or is it possible to have a low quantity of oil without triggering a low pressure warning? If low level should generally trigger a low pressure warning, how much would the level of oil need to go below of the 2.9l capacity to reflect in a warning?

Oil warning light will work of a pressure switch. If it comes on that is very bad news as the oil pressure is want keeps the plain bearings working, without it they run metal on metal.
Oil would have to go very low to do that. It could be the wire shorting out? I think a mechanical bearing or oil pump fault can also flag it up too.

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