AE86 digital dash wiring

[CHB]

any one knows which wire from the ECU that sends signal to the digital RPM meter on AE86?

[CHB]

Help... Anyone?

[jazae86]

The signal comes from the tacho, not the ECU. Analogue/digital dash same.
Black wire, orange dots from memory.

[Chrisso]

I think it comes from the coil/ignitor negative, or at least that's my recollection of the wiring diagram. If you don't have a copy of the wiring diagram, then search for posts by Parrot. He's linked to it many times on here.