speed odometer

Surely you mean that the speedo needle is unstable. Check for poor connections from the sender and/or poor sender (on rear cover of differential [final drive]). also check connections on rear of instrument panel. Odometer tells you how far the car has moved.

All the best, Peter.

I had a mechanical speedo that jumped all over the place too. I think it must've been a mechanical fault in that case at least, because adjusting the path of the cable inside the dash slightly would vary how much the needle jumped around. In the end the car rusted out, so I never did find out why it was happening.

Allan.

Heh - I suspected the dry option at the time - put in some oil - and it jumped even more. : o

A mechanical speedo that jumps is either a dried or kinked cable, or rubbing of the magnet inside the speedo. In this case though the speedo is electronic, usually the cause of jumping is either the wiring rotting out back by the sensor under the car or bad solder connections on the circuit board in the speedo.