I am a retired Technical Trainer for JD. We taught a seven step system for diagnosis of a product concern. #1 step is "know the system", the two posters below do not know the system.
Electrical power comes from the Ignition switch through a 25 A. fuse located in front of the dash. Power flows to the #3 terminal on the Time Delay Control Module. When that module is satisfied power flows from the #2 terminal and feeds power to all three ignition coils, one for each cylinder. With the switch "on" you should see 12Volts at all three coils from the orange wire that is common to all three.
There are three Pulsars in the flywheel housing located each 1/3 the way around the housing. Those Pulsars signal the Transistor Module which in turn controls the ground side of the individual coils. Each coil has two wires, one to feed voltage (orange) and one for the ground. When the Transistor Module takes ground away from the coil it creates a high voltage surge to create a spark from the coil. Yes these coils fire the spark plug each time the piston gets near TDC.
This is a system similar to what you have on your auto or pickup if they are newer than about 97.