Well if you put the head on an ohm reader and it jumps around at all it is a short.seems odd still that the protank coil(s), even the clean..er ones, are all reading so high, and the cheapo tanks (rated at equal or higher resistance) are rating lower. I'll change all the coils out and see if it's still happening. btw, I'm assuming you mean a short in the coil, not in my mod, right? I think I may not be cleaning the coils right. will keep banging away. All this banging, though. I'm getting sore.