I'm convinced the buzzer in addition to the light is the way to go. A few seconds is the difference between a saved engine and hunk of junk.
I bought the buzzer today at Radio Shack. It's a Piezo 273-080, high instensity slow pulsing, 9-16 V, 300 frequency. It was about $6.00. It's an automotive warning buzzer. I think I will hear this buzzer over the pipes.
I also got an idiot light
oil sender, small GM type, Car Quest #53-33508. I tapped into the
oil sender tube by the
oil filter on my 302, to put the new sender. This sender is grounded until the engine builds about 3-8 lbs. pressure and supplies the ground path for the light and the buzzer. So I have two senders, one for the gauge, the other for the light and buzzer. I'm still working on the wiring. I'm considering the 555 timer module, but am not sure about the wiring, or may use a time delay relay or a time delay switch.
My intention is to set the timer at about 2-3 seconds so the buzzer does not come on when I first start the car, but the light will be on a few seconds until pressure builds.
Thanks.
Wayne