Your two alligator clips connect to the terminals on the battery. Your missing hall-effect sensor would have illuminated the light when the high current passes through your #1 or #6 spark plug wire to fire the plug.

Jim's setup is a little different. The coily thingy attaches to the top of the #1 or #6 spark plug, and the boot for the spark plug wire goes over the top of the coily thingy. Then the alligator clip that Jim showed attaches to the coily thingy to get the signal to illuminate the light. Jim's light would have the two alligator clips that go on the battery as well.