You can ohms test the coils stator and trigger bit the switchbox is only by process of elimination. To better test the system after replacing the stator with a correct one, would be to do an ohm test on the coils and trigger and see if they are ok ohms wise, replace the appropriate stator, turn the ignition key to on several times and make sure there's no voltage to your kill wire. That's important because voltage on the kill wire can kill your switchbox immediately! If there is disconnect the kill wire(you would have to choke the engine off at this point) then try to start it and see if there's spark. If Sparks not there or weak you then need to dva test the peak voltages to and from the switch box to see which component is at fault.