I've built in a new transmission since I've lost my tacho signal.
I'm not stupid, I've built my old gearbox into my new one and see that tacho goes back.
just way too fast
because as I could read from the schematic is from bj. 92 the encoder has been changed from 3 pole (hall ) to 2 pole (inductive ).

and thus probably also the signal wheel.
tomorrow will try to reinstall the old 3 pole and a line with clamp 15 to pin 1 from the encoder with clamps.
then it would have to go

Mfg. Marcus