Oil pressure gusage issue?

If there was a genuine zero oil pressure there would have been a hell of a row from various engine components.
It was still full of clean oil.
Much more likely a filthy spade connector etc, anyone on here know what open circuit does to the gauge?

Eta misspell

Should have added - accuracy not too much of a concern to me - the main reason I look at the gauge is to see if the pressure is changing. My first Griff (the 500) had zero oil pressure when I bought it but it was running fine. Got a good chunk off the asking price though!

I believe this is quite a common issue. And I've suffered similar symptoms twice with two pressure senders.

I was told that as long as the red oil pressure light on the dash doesn't illuminate you're fine. This light is wired to a separate sensor, so a failure of the gauge does not affect the light. But check that it illuminates when you turn on the ignition, to test the bulb.

As you've spotted, the pressure sender sits in a very exposed place so is susceptible to getting damaged or dirty.

Does the oil pressure gauge show a reducing reading when accelerating/decelerating? This can indicate a loose electrical spade connection. If it is failing when the engine is warmed up/hot, then the sender is probably on the way out. Or if it fails randomly there could be a leak/poor seal at the gauge union that is disrupting the reading.

I've gone through two senders, but have been driving with the second temperamental one for a couple of years. If I change it the next one is only likely to fail too and I'll have wasted my money.