VDO RPM indicator problem

A year ago, I reported my VDO lap account issues on this forum.
The VDO rev counter indicated intermittent inconsistent speeds, such as 7000 rpm
Here is the solution after several months of testing: two anti-interference ferrites, and above all a screened cable with two conductors and a screen.
look at the drawing.
Attention, connect only one end of the shield to the aircraft ground
The connector supplied with the motor is retained, on which the shielded cable is soldered.
This connector stays as close as possible to the engine, and its two original wires are folded up like an "accordion" and attached as close as possible to the engine, so as to keep the shielding protection all along the path of the wires going to the rev counter.
I have tried several things, but it is the simple solution and it works best!