shift light, 2000 mazda protege

hey all, i'm an installer new to the forum and wanna say hi to everyone, so... hi. now that all the hello's are out of the way it's time for my first question, any and all help would be greatly appreciated. i'm installing a proform shift light in a 2000 mazda protege es (1.8L, 5spd). the shift light has 6 or 7 wires coming out of it but the guy who gave it to me had all but three wires cut off, which apparantly is all i need for a 4cyl application. anyway, the wires that are left are a red, black and a green. the red and black are self explanatory and the green obviously is for the tach. i got the red and black hooked up easily enough and i do have an effective power and ground as tested with a multi-meter. the green is where i'm confused. i tried wiring it into both ground wires on both coil packs and also into the PURPLE / white tach sensor from the diagnostic port under the hood, but nothing. i rev it up and get absolutly nothing, it won't light up at all. i verified that all electrical connections are working and that of course the bulb works, so i have it narrowed down to the fact that i am not wiring the green to the right place. does anyone know where i might wire this to actually make it work?

Zoom-Zoom

Can also find tach in pin 48 of the ECM.Jeff

Velocity Custom Home Theater

Mobile Audio/Video Specialist

Morden, Manitoba CANADA