Sharing some info on a recent fix on my 92 instrument cluster. Everything was working except for the odometer/tripometer. Speedo worked, cruise worked, etc. The only loss of function was the odo/tripometer. Long story short I found issues with the PCB that drives the speedo unit inside the cluster. The 150uF capacitor was shot and there was a break in the printed circuit from this capacitor to the next resistor in the circuit. A replacement capacitor and a jumper wire from pin to pin solved the issue! Very cheap fix but troublesome to diagnose for sure. I spent a good bit of time on it and I'm sure others have the same issue.

(shining a flashlight under the PCB makes the circuits REALLY easy to see. Use a meter to check continuity from point/point. Pics below:

This is for a 110MPH camaro speedo unit. Not sure if other models vary. I have extra capacitors if anyone needs one.

Bad printed circuit:





Jumper soldered on to restore the circuit: