[tbirdtbird]

last i knew the coil secondary grounded via the can; the other end of the secondary is obv. the high voltage coil wire. An automotive coil is in essentially a DC transformer, with 12 v in and 10-15 K volts out. Of course, DC voltage doesn't fluctuate so this violates the principles of a transformer. BUT add the points to make and break the primary and voila you have fluctuating voltage after all