Speedo issue

[Linkachu]

This is the best place to get noticed, sorry but i have to.

My EF speedo is not working. Had 3 clusters in there, swapped out the Speedo sender from the gearbox and the loom at the firewall is fine.

Its been to an auto electrician but i might take it to another if i cant find the problem with your help.
I have heard something about a micro computer going and that stops the speedo working, but where is it located?

Everything works fine except the speedo and ODO do not work at all.

Cheers.

[XDV800]

The gear that interacts with the transducer on the output shaft then.