If you have the original wiring, the coil wire is a resistor wire. If you're replacing the coil, get the one the book calls for at the parts house, and replace. The coil will call for a ballast resistor which is purchased separately. Ignore that, and install the coil using the resistor wire in your wiring harness.
you didnt say if it is stock or what. if it is after market put a balast resistor in line with the wire to the positive side of the coil chief