Glad you figured it out. Coil was my first thought as I have had several over the last 35 years do exactly what yours did. That is another reason I personally would not run that kind of coil on a street car. When a ballast resistor goes bad it will prevent you from driving the car until you replace it or jump it. I'm guessing the internal ballast lost some of its effectiveness and fried the coil. It may have also damaged that pickup coil as well, I'm sure it didn't hurt the new one as you didn't run it long enough. Keep us posted.