oil pressure gauge hookup?
I have a Smiths oil pressure gauge (electric and not connected to anything) and yesterday I discovered that I have something that looks suspiciously like an oil pressure transducer mounted on the spin off filter adapter. There are 2 devices on the adapter - one is my oil pressure idiot light (I know this by my mighty powers of deduction - there are wires going to it and something must be switching the little idiot light on and off) and the other which looks like a rusty little can with 2 spade lugs on top and has no wires going to it.
So I ran a wire direct from one of the prongs to the back of the gauge, and another from the power side of the gauge to the battery. I provided a ground to the case of the gauge. Nothing. Tried swapping the wires. Nothing. Oh - engine WAS RUNNING.
Am I doing this right? Or should there be a ground down at the transducer itself? Are one of the spade lugs for ground and the other for power? Does the gauge work similar to the fuel gauge (hopefully just not as intermittently) where the gauge works off of a variable ground resistance?
Does anyone know how I should be wiring this thing? At least to the point where I can trouble shoot if the gauge or sender are bad?
Mike
1969 Series IIa 88 2.25 petrol