How do you fix an Rpm gauge on an infiniti?
If you either get no rpm or its erratic, then change the Instrument cluster as one unit. RPM cannot be fixed or changed. You either have to buy a used unit from a junk yard or buy the cluster new at the dealer. Its expansive, I would buy a used one from a salvage yard for around $75-150. Good luck. I have 15+ years as an automotive technican. Trust me.