Hey i have an 04 gt and i just got a frpp tach adapter off this guy, It only has three wires on it black red and green the pig tail adpter was cut off but he told me i wouldn't need it unless i had a automatic which i don't. So heres my question, how does this thing work i am hooking it up to a auto meter shift light which also has the same three colored wires i am assuming the the adapters red is a 12 v source the black is a ground and the green is hooked up to the green on the shift light but isn't that the same as just hooking it up to the shiftlight i geuss what i am trying to say is what wire from the box is going to pick up the tach signal if all the wires are accounted for. am i missing a wire did i really need the pig tail any help with this would be greatly appreciated. 
thanks
jim
thanks
jim
