bad ignition?

i was checking out some wiring on my dyna s and the hot wire coming from the pickup coils makes the test light go on when i touch it to the positive side of the battery. then when i turn on the ignition and hook the test light to the neg, terminal of the battery this also makes the test light come on which should be right but i cant see why it would come on on the pos. side with the igntion off? I got sooty plugs and am only getting about 8 volts across my coils.