Originally Posted by DrB
So I went to the boat today. Changed the oil filter, pulled the sender, and put in new oil; in that order. Sender looked fine, not plugged with stuff. I didn't have a mechanical pressure gauge to try, so I reinstalled the sender and jiggled the wire some.
After I turned the key to on, and before I pushed the start button, I looked at the oil gauge and it was pegged, without the motor on. The other gauges hadn't moved. I am more convinced now it is a electrical problem or the oil sensor itself.
Thanks all for the advice.
If you used anything other than a Yanmar sensor with a Yanmar gauge you have to understand that Yanmar makes theirs where they will not work with other manufacturers senders or gauges, it either has to be both of them Yanmar or neither of them Yanmar. If you have that part right it could be wiring, or the gauge, the only way to know is to swap and test, or at least the only way to easily know.
I personally would have swapped out both the sensor and the gauge for a teleflex gauge and sensor or some other aftermarket set. The Yanmar ones are pricey enough to pay for both pieces with the swap out. You cannot mix the Yanmar sensor with any other type of gauge or the Yanmar gauge with any other type of sensor, they will not work, and will peg the gauge over every time.