No Power in the car, but there is in the engine bay

Just got a brand new battery and after having spliced my aftermarket gauges into my headlight switch, I went to test them out and there was no power at all. No crank, no lights, nothing. The battery reads 12.6v but when I go to turn the key, nothing happens. Ive been reading lots of forums on here and tried everything they said, but still can't figure it out. I can turn the motor over but jumping the starter relay, the alternator reads 12v when the key is in the on position, I then checked the fused link and that is also good. I have power on the engine bay side of the bulkhead for the ignition switch, and when I turn the key on, my voltmeter turns to 12.5 volts(I have it connected to something in the engine bay, I think the voltage regulator) But there is no power at the fusebox, but I do not see any reasons as to why. Any ideas????