hi,I'm new to this forum,so if you older folks could help me out,I'd be very thankful,I've been doing some searching on these forums on how to hook up a after market tach,well i have a 2000 f-150 4.2 v6 and i have a pro sport tach that is adjustable for many engine size's,i have the power,dimmer,ground all hooked up,but i cant for the life of me find out where to hook the green wire to to get signal,the guy at summitt told me i need to find the lead wire(or signal wire) and tap into that,and my tach needs a 12v neg off the coil to work,so does anybody know for sure which wire on the coil pack is used for the signal wire for a tach??????,i tried taping into a white and pink or red wire, not sure wire was dirty and hard to tell what color it was,but it was coming from the pcm on the firewall and that didn't work,and I've also hear that the white/pink wire on the coil will work,but i want to make sure so i don't fry my pcm,could somebody plz help me out here,cause i don't really want to spend the money on a adapter,but i guess i might have to,so thanks in advance.