Speedometer issue

[Max rudar]

Speedometer act crazy with needle sometimes jumping from 0 to current speed but mostly dead to 0.
Did try changing the whole instrument panel and also speed sensor from my friends 80. None worked.
Its 96 turbo diesel 24v.
What else should I try?

 

[ppc]

Bad grounds can cause strange behaviors.

 

[Max rudar]

Forgot to mention odometer doesnt work when speedometer dies.