Update:
Did some research today. I believe Gaz64 (Gary) is on the right track. I found a U.S. patent issued to Susuki Motors in 1993 using a sophisticated circuit off the S terminal to active a very accurate
oil pressure warning light. It has several diodes and tranisters that I can't duplicate. I do think Gary's option is viable.
Gary, I have a old style aternator with a separate voltage regulator. I didn't intend on wiring the "I" terminal with a warning light. Is this the terminal you suggested tying in the Buzzer to? I could run a wire with a 15 omh resister if needed fron the ignition switch to the "I" terminal. More detail please.
Wayne