problem with defi rpm gauge

[Project D]

To make it work properly you need a proper square wave like defined in the manual:
http://www.defi-shop.com/installation/manual/

The Coil signal is a "spike" type, so you definitly can't use it properly...

The Ne signal is supposed to be a square wave who oscilate between 0 and 12v (if you have an oscilloscope to confirm...),
so with the blue wire (not the light blue on the old "BF" or "Racer" serie) it should work.
If not, then I don't know...

You can also try on the IGt signal, it's a 0/5v square wave (so still the blue wire of your gauge)
->Not really recommended because it's the signal who actually make the coil working. It will not dammage anything BUT it can result in bad firing for your engine.