If there was a short in the wiring between a voltage source and the sensor wires, wouldn' the fuel INDICATORS go crazy ? Wouldn't that be recorded on one of the 'blackboxes' as occurring just prior to the explosion ?
If that were true, don't you think they would have shown that as proof ?
We're straying from things I know about to stuff I have to take the word of others on. Too bad my 747 mechanic father isn't around to talk about this.
However, I kind of recall that there were a few odd indications a couple of minutes before the explosion that the pilots discussed and was captured on the cockpit voice recorder. IIRC, one of them was a tank level or something related. I believe the other one was a higher voltage system, and that both circuits ran in the same conduit. I think that is what lead the NTSB to their theory.