Could you have broken down the insulation/resistance between the primary and secondary in your coil from the hi current? Three meg. can't be right. Is that the wire resistance with just the DVM connected to the ends of the wire? I have had a condensor go bad on a nailhead motor that killed the spack then after cooldown measured ok. Condensors are electrolytic type capacitors. They have a wax or oil type dielectric which can "heal" itself it to lower testing voltages such as DVMs and removed from heat.
