"Nice try, Sparky," from Tony, who by now must be bored with all this. "Fires are easy to investigate even when all that's left is a pile of ashes. Only 1 out of 20 are written up as 'unknown origins.' Not good for you. But the real problem is that when a 12-volt DC circuit overloads, the insulation often burns off and the strands of wire may show some melting. When it happens with 110-volt AC, the entire circuit usually melts away. Easy to spot." Damn, I pay for another round and give it another try. "I'd take the same AC power cord and blast my old GPS and radio, fry the circuits, and say it was lightning."