How to know when you have a good 6 volt neg ground coil and how to test un marked coils when you don’t know if they are 6 or 12 volts and positive or negative ground?
Also do coils get week ? How can I know which coil will give me the best spark? You order a new coil from a parts store, “hey I have a 41 Buick, need a good strong coil.” He throws a box at me, “here take this one.” How do I test this new coil under running conditions, before i spend 100 $ having it installed?