I've had 2 coils go out & in both cases once I got the car/truck back home in the parking lot (coil had cooled) I was able to generate copious sparks out of the coil center terminal (coil wire held 1/4 from ground) by dragging the male tip of the body half of the dist pickup across the metal intake (key on of course). they popped/missed/backfired (in the carb) & finally died & on the car deal after acting up for a half hour on the road on the way home it finally exploded the muffler and the guy in the next lane just about wrecked getting out of the way & likely thought he was being shot at. EDIT actually the backfire was out the tailpipe not the carb now that I recollect