I have a 92 Firebird the speedometer is working but the odometer is
not. I have exchanged the odometer and instrument cluster and it
still doesn't work any input would be appreciative.

 

Both speedometer and odometer are driven by the same 12v IGN, ground and speed signal input. If one works and the other doesnt, then the in-op part is defective

Strange that even a replacement is broken, but theres really no way for one to work and the other not to without one being bad

 

I check a auto-electric specialist and he agrees with you that the
ground would not be the cause of just one failure but would cause
both the trip mileage/odometer and the speedometer to not work
togeather. The speed signal input is not the problem. The speedo
sensor may be involved there are three types do you know where
the stamped trani number is?

 

Did you figure this out? I have the same problem. My speedo works but the trip meter stopped 2 years ago. The discovered my odometer stopped working last year. Took to a speedometer specialist and they said there is nothing wrong with the cluster side (gears and motor(s) work perfectly fine with direct power connected). They said if it were the speed sensor then the speedo would also stop working.

They suspected the circuit board in the instrument panel may be malfunctioning but he said it was only a GUESS as they are stumped...

 

I located the problem with my odometer gear, and it occurs throughout
the 92 range Firebird, inside the speedometer is a small double layer
gear that works the trip odometer. These double layer gear brakes down
in the Florida heat and becomes britel and then becomes a plastic powder.
I've checked three differant dash clusters from 92s and they have all worn down.
I've tried to locate a distributor for the gear but have not found one yet.
If you know of one let me know. I have pictures of the gear in attachment.