Truck is a 54 Chevy 235. Yes, the gauge was calibrated from 0-30 ohms last February and rechecked today at a local speedometer shop. It was right on the money. I watched them check it on what I would call a Resistance Checker box with a rheostat knob and a number counter, set at 6 volts without the Runtz. He checked with the Runtz on at 12 volts and the gauge hardly moved even as he turned the knob up. The truck has an AC Delco 1959 12 volt 30 AMP generator with a power steering pump on the back, Model 1102115. No, the battery cable has never been removed while the truck was running.
