I replaced the drive belts on my early 71 Z about a month ago. I also replaced the alternator with that of a 280z. After this, my oil pressure gauge stopped working outright. Even after driving it for a bit, it does not move at all. The engine temperature is reading. Just trying to rule out the problem, I bought a new oil pressure sensor, and now I can't locate where the old one is. Any help would be appreciated. I have a general idea of where things are in the engine from my repair manual.