1990 R2500 Suburban speedometer not working

[vista_burb90]

For a while now my speedometer will hold at about 65 when running. Sometimes the needle will fall all the way to the right when off. Sometimes needle will end up at far left and then bounce when running or sometimes just hold at 0 when driving. Kinda odd…
Trip and odometer has no issue tracking mileage.
Cruise control works and shifts great too. Can anybody confirm my thoughts leaning toward a bad gauge?

M40 — TRANSMISSION,AUTOMATIC 3-SPEED(THM400-475/3L80)

Thanks!

 

[HotWheelsBurban]

For a while now my speedometer will hold at about 65 when running. Sometimes the needle will fall all the way to the right when off. Sometimes needle will end up at far left and then bounce when running or sometimes just hold at 0 when driving. Kinda odd…
Trip and odometer has no issue tracking mileage.
Cruise control works and shifts great too. Can anybody confirm my thoughts leaning toward a bad gauge?

M40 — TRANSMISSION,AUTOMATIC 3-SPEED(THM400-475/3L80)

Thanks!

That was my last square body Burb, but I never had that problem with it.... If you could get another gauge cluster and swap the speedometer out, that would confirm your theory....
Back in the day, this type of thing was usually a bad or loose speedometer cable. But these speedometers are electronic and run by the PCM (I think?).