The coil is simple. The "HOT" wire is always live when the key is ON. The black wire from the distributor is the "grounding" wire. It goes from the other side of the coil to the points in the distributer. You can test the coil by turning on the key, taking that ground wire and tapping it to a bolt on the motor. Every time you lift off the bolt you should get a spark. DO NOT leave the ground on for very long. The coil will get hot and burn out.
68 Mustang Fastback
Lentech AOD, 357 SBF, Vortec S/C, F.A.S.T. EFI
NEVER DRIVE FASTER THEN YOUR GURDIAN ANGEL CAN FLY...