Anybody had any problems with hteir block heater shorting out. I finally got around to digging it out of its little hiding place so i could use it. It worked nicely the first couple of times. Just the other day I plugged it in and heard this zapping sound under the hood. Did a little snooping around and could not find anything wrong. Went in a checked the breakers and one had blown. Any body have any idead as to where the problem could lie?