The way you show your voltmeter, it is powered at all times. It will draw enough that when parked for awhile, it will eventually run down the battery. Run it through the key
Why did you do away with the alternator black. If you simply bypass the ammeter, then run a large gauge FUSED (or breaker) wire direct from alternator to battery, the black and red through the bulhead then work together to feed power into the pass. bay. This adds "more wire" size and is not a bad thing.
I believe "Crackedback" on here sells those bypass wires.
