tachometer is not working?

Hello,

This could be due to a faulty cluster.
Try this procedure to do a self-test of the cluster, this can tell you if the issue is the cluster or some other component.

Begin the test with the ignition switch in the Off position.
Press and hold the odometer/trip button.
While keeping is pressed turn the key to the on position (do not start).
Release the trip button.
This will trigger the self-test of the cluster.
The cluster will begin to illuminate all of the lights and the gauges will sweep to predetermined calibration spots.
If the tachometer gauge fails to sweep through the calibration points, the cluster needs to be replaced.

https://youtu.be/_HEC44xENxw

I have attached little more detailed information on the test.

Please let me know of any questions.
Thank you.