I'm hooking up a Autometer C2 tach and shift light on my 01 mustang.. I've been told by many you don't have to have a tach driver... I hooked up black, red, white, and tried to hook up gree wire but I believe its on the wrong wire... I can push red button on tach and it shows when the shift light should come on and I can pull the headlight knob and back light will light up but I go to turn on car and the tach never moves off zero.. If someone knows which wire to hook green into please let me know thanks..