On my 1971 Buick GS, when I turn the key to start, but don't crank, the oil pressure gauge is at the low point. When I start the car, it shoots all the way up to the high point. Is this normal? When I disconnect the gauge, it still reads high, but when I turn off the car, it only falls about 1/4 of the way down.
Should go all the way down. I would have gauge serviced. Is gauge original? What sender are you using?
The gauge does look original and seems to work. I have no idea what sending unit it is, but I may not be original. Is the oil pressure gauge test like the fuel gauge? When it's grounded, should it read L?
May not be original to the car, here's why. Original oil light in a non-gauge car had a test sequence when key was in START. Light would come on & then off when the engine started & key returned to ON. The light was seeing 12V at start via a green jumper in the steering column wiring harness. Original gauge in a car had a slightly different steering column wiring harness. The green jumper was not installed, eliminating the full 12V at start. Gauge saw only the variable voltage from the sending unit on the engine. I converted mine to a factory gauge set-up & trimmed back the green jumper.Worked as factory. With a Chassis Manual & a sharp eye you can spot the difference on the diagram.
