No pwr to the fuse box at all? When you put a test light/multi tester at the spots marked bat there is no pwr? Or just no pwr to your dash?
Check your pwr coming off of the battery. Your main pwr (6ga cable) goes down to the starter solenoid and from there branches off to elsewhere around the car. Also check your ground cable from the battery to the front of the block just below the AC compressor. Check for any corrosion and insure good contact to the battery. Make sure the cables arent burned up. You also have, I think 8ga, going to the alternator from the battery, but I dont think that would have anything to do with what your describing.
