Ditto all above, and the coil wire is the one with the 90* boots at each end..probably they just like you a gave you an extra

 

Some sets come with 2 coil wires to allow for different vehicle application. If one checked, that same set will wirk for another vehicle. Keeps mfg costs and inventor costs down. One extra wire cost is less that inventory cost.

 

Thanks for the replies. I'll use the double black boot one for the coil and toss the other

 

It can be used as a spare. Why toss it??

 

Maybe it connects to the flux capacitor or the knuter valve. Then again it could also be for the fetzer valve. I'm sure the FSM will have it.