Ram B250 Odometer problem

Hello,

Since a few weeks I own a 1993 Dodge Ram B250 Conversion Van.
Only, with a not working Odometer.
So I have taken the meters out and found out that the little motor at the back of the Speedometer was missing.
Probably taken out by the former owner with the idea that it causes the problem of the Odometer.
Bought a used meter cluster and replaced the little motor and also the print board to which it is connected.
But apparently this was not the reason that the Odometer don’t work. Means, he still don’t work.

Conclusion, it is probably caused by something else, wiring, sensors, or ???


Is there someone who have any suggestion and/or ideas of things to check, or what probably causes this problem?

Greetings,
Jac.