I bought a couple of neat things from VANS. The first is a manifold for multiple sending units. I think it was less than 20 bucks. The other thing is a switch that goes in the oil pressure circuit. It has one contact that is normally open and the other is normally closed. The third is for power or ground, depending on how you choose to wire it. The switch activates at 15psi. I have the NC side connected to a BRIGHT RED LED on the panel showing that oil pressure is below 15psi. When the oil pressure goes above 15psi the light goes out and the NO side of the switch closes and starts the Hobbs meter.
