Hi Jeff, when the senders go they pin out all the way to 120 when ignition is on even without the engine started. I am 90% its that although I replaced a set of triple gauges last week that were faulty. If there has been any dampness in the car the backs of the gauges and the copper contacts can become fouled.
Get an oil pressure sender first and that should sort it and if it doesn't drop me a PM
Lee