If the above speedometer does not function, examine the speed sensor pickup and change it if it is bad. Check for corrosion of the terminals, loose connections or the broken wires connecting the speed sensor to the speedometer and rectify. To check the correct function, fit an assured fine speedometer; if it runs fine, then replace the speedometer assembly. For an intermittently working speedometer wiring should also be checked and cleaned or repaired if necessary, and on the speedometer itself there is the speed sensor pickup which should be replaced if necessary.