oil pressure Gauge no working

My best guess, loose contact pin on circuit board. Oil gauge signal is the only gray wire in that round connector. If that contact pin is loose/broken, you can try solder board repair or simply cut the wire out of that connector and route it directly to the sender side of the inst'.
Ring terminal, toothed washer, and nut just like the ALT' gauge has, installed on top of the OEM speedy nut works just fine. Not all inst' panels have printed circuit boards. Instead, every wire is attached where it terminates.