My experience is with the 240s, b230F engine but this may work the same in the 740s.


The oil light comes on when the lead from the light gets grounded.

Grounded anywhere. Properly operating, it is grounded inside the sensor when the oil pressure is below, I think, 5psi. At start-up, the pressure is zero, thus the light. After starting, the pressure rise shuts off the light.

If the lead from the light grounds anywhere, the light will come on. Thus George's point of checking the wiring.

OR, the pressure is indeed below that lower threshold. Oil pumps do get weak, and oil in the pan can be moved, under acceleration, to being away from the pick-up. The oil is at proper level, right?

Good Luck,

Bob

:>)