Eratic Speedometer

[cascabel3]

Sometimes it works just fine, other times it goes to 25 mph standing still, at times it alos just jumps while driving. I have a 1993 Vectra DP on a Spartan.

[cascabel3]

Sometimes it works just fine, other times it goes to 25 mph standing still, at times it alos just jumps while driving. I have a 1993 Vectra DP on a Spartan.

[Gary RVRoamer]

Do you know if the speedo is electronically driven or mechanically driven? Mechanical cable driven speedos get erratic like that when the cable is binding or broken. Replacing the cable solves the problem.

Electronic speedos get erratic when there is some kind of electrical fault. Maybe even just a bad ground in the dash board unit. I don't know a lot about them, so can't suggest any likely sources of the problem.