Wrong- - - -a regular oil pressure switch grounds with no pressure, and open-circuits when running to turn the light off. There is a 3-prong switch used on GM fuel injected engines with two normally-open contacts, closed by oil pressure. Wire one contact to a constant 12V source and the other to the input of the hour meter. There is also a normally-closed ground for an idiot light that won't be needed for your application. Try looking up an oil pressure switch for a 1976 Vega- - - -that's the one I usually ask the computer jockey nose-picker for at the big box parts stores.

Like this:

http://www.rarenosparts.com/assets/images/BOXA18146.JPG

Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!