1999 Chevrolet Tahoe Electrical

How did you short the battery? I hope you didn't hook it up backwards? Get the battery charged. I would check the amp draw, everything off. Usually shouldn't be more than 50 ma if that much, that is.050 amp not even a tenth of an amp. If the drain is too much, pull/replace fuses one at a time, when you pull the fuse on the problem circuit, the excess drain goes away, then you check everything on that fuse circuit.

Check for any lights left on, exterior--interior--under the hood, everywhere. Best time to check is in the dark.

If you think it is the alternator, take the bat terminal loose, just don't let short to anything. See if it helps?