Tachometer drive not working? Derbi

Hello,
Recently I switched to my new set of wheels to from Enduro to Supermoto!
Me and the guy switched the tachometer drives too, cause of the difference of the wheel size and travel.
I installed the drive and it did not work. Showed 0km/h constantly. The drive is digital and spinning as it should, but not working. Could this be a mechanical problem or a problem in the wiring? Does anyone have experience?

This is the digital drive.

Thank you.

 

The wire.
They seem to stop working quite quickly, I've replaced a few on warranty, maybe like 20 or so over the years

 

Okay! I think I just remembed seeing only 2 wires at the start of the drive wire, not the 3 as in the pin connection. Huge thanks!

 

Hey! I checked the wiring and it seems to be okay. The only thing is that the whole chip with also the wiring comes out. Is there a fix to this? Are there cheaper alternatives for a drive? £50 is quite expensive for such a small Derbi component.