What would cause a 91 Mazda 626 tachometer to quit working?

A 1991 Mazda 626 tachometer may quit working due to several potential issues, including a faulty ignition coil, a broken or disconnected tachometer signal wire, or a malfunctioning instrument cluster. Additionally, a bad engine control unit (ECU) or issues with the crankshaft position sensor can disrupt the signal needed for the tachometer to function. Checking these components can help diagnose and resolve the problem.