Please help me tachometer gauge
 

I have a 1999 impreza turbo I'm trying to wire in a rpm gauge and ran in to all the normal silly mistakes I ran it to the coil but it only showed half the revs I was using I've now learnt it has split coils so it will be best wired in to the ECU but I have found 12 conflicting diagrams for what pin I need does anyone know what pin I need and what colour the wire is please help I'm seeing wires in my sleep. It's a 52mm digital rpm gauge wired for power just need to know where to go next. I also looked in to going in through the cluster but again had conflicting search results some said I could go through stock tacho and others that that won't work and again no one knows what colour the wire is please help

Never mind after a very long night on the wonder that is google I found what I needed it's now wired straight into the cluster harness an orange wire with a white strip that I confirmed at the ECU to be pin 14 B135 ( the middle connecter ) works like a dream has a warning light at 5k RPM tried to use it as a shift light got to 3rd gear and decided enough poo had entered my boxers. Thank you to anyone who tried to help. :)