I think you have to take apart your dash, get a haynes manual or of the like.
you have to replace it
Nissan terrano 11 techometer not working
To fix a 12V diesel tachometer, first, check the wiring connections for any loose or damaged wires. Ensure the tachometer is receiving power by testing the voltage at the input terminal. If the connections are intact and powered, inspect the sensor or signal source, typically a magnetic pickup or alternator signal, for proper operation. If these components are functioning but the tachometer still doesn't work, it may need calibration or replacement.
To fix a tachometer needle that is stuck on the wrong side of the resting pin, first, carefully remove the tachometer from the dashboard. Gently pry off the glass cover to access the needle mechanism. Use a small tool to nudge the needle back to its resting position, ensuring it sits correctly on the pin. Reassemble the tachometer and reinstall it, checking that the needle functions properly before closing everything up.
The tachometer on a 1991 Acura Integra is wired through the dash. To reach the wiring remove the dash console and pull out the tachometer. There the wiring can be worked on using a spark tester to find the bad wire and solder unit to replace the wire.
An optical tachometer works by using a light beam or sensor to detect the reflections off a rotating object. By measuring the frequency of the light reflections, the device can calculate the speed of the rotating object. The tachometer then provides a numerical readout of the rotational speed in revolutions per minute (RPM).
clip it on your distributor cap
run a new line to the distributor.
Std. transmission could be "shift" light
Did you ever find out the problem? I'm having the same issue.
Check engine light : Gauge cluster without tachometer ( under the engine oil pressure gauge ) Gauge cluster with tachometer ( just to the left of the battery voltage gauge )