TL;DR: My previously perfect electric oil pressure gage is now pegged after an R&R. Why?
Over the past few weeks, I've been working a tiny bit at a time on installing a factory tachometer in my '77 Grand Prix. Like most car work, it was more complicated than I expected. I bought a complete gauge cluster with the factory tach, had the electronics upgraded to modern stuff, and then swapped the gauges (to be pedantic, they're meters, except the speedo) into the purchased housing, polished the clear cover, and put it in the car.
The good news is that the tach works fine. The bad news is that my oil pressure gauge (meter) is pegged (reads all the way to the right, well past the max value). It functioned perfectly before. The voltmeter reads correctly, and the gas and temp gauges appear to be functioning normally.
Each of the minor instruments have studs in the back that insert into a pair of pincers to form the electrical connection. It's impossible to connect it backwards or to fail to make the connection, everything looks nice and clean, I was careful and gentle when I moved them from one housing to the other, and I didn't mess with the wiring behind the panel that the gauge cluster connects to. The tach has separate, independent connections.
Any idea what I screwed up?
