Hello everyone!

I've recently bought my first car: A 1994 Mazda 323 Astina BA Series 1 manual.

And just for fun I've bought a little shift light (because racecar okay haha) and I was hoping someone might be able to provide some info on where - and how - to actually wire it up.
I've seen online, people wiring tachos (similar to the shift light) to the distributor; the negative terminal on the ignition coil and sometimes the ECU.

The problem is I'm not sure which wire (from the distributor) will output the tacho signal for the light. I also can't find any sufficient wiring diagrams for tacho signals from the ECU. (PS: pictures would be great )
If anyone has done this or something similar to their car, I'd greatly appreciate any help

Thank you