Tach stopped working

[GRWeldon]

So my tack just stopped working. I have replaced the odometer gear and I'm wondering if I may have disturbed something. Going to pull it again and see.

Isn't this a symptom of a failed crank sensor? Do the stop working just like that?

 

[theterminator93]

If the engine runs, it's a problem with the gauge. Reseating the cluster connectors and popping out and re-seating the tach in the cluster are worth trying. But I've also seen tachs fail completely too, so having a known working spare handy would be a good idea before you pull the cluster.