Much easier solution. If you look on the passnager side wiring harness by the top of the shock tower, on the in-car side of the harness there is a one wire plug (usually a blue/silver wire, or something of the like). It's usually covered in a little rubber boot and taped to the top of the harness. This is a factory tach test lead (for hooking up a tach in the engine bay to check idle and such). You can just clip that wire and run the green wire to that and you've got your signal. Good luck. Seeya.