2003 Jimmy 4.3 Battery drained down every few days and had to be charged. Today the battery was dead. Replaced it.

Check the glove box light,make sure it goes off when closed.

I'll try to help, everytime something gets replaced on these yukons, that circuit needs to be RESET ! Is there a reset button, on your steering wheel, to reset a variety of functions ? , check owners manual, or call your dealer for better advise

First you can not test an alternator by disconnecting the battery cable. That is what we did back when cars had generators. Today you can fry the computer and alternator running the engine with the battery cable off.
Meanwhile, I would look for a fuseable link or main fuse problem. The alternator circuit may not be connected to the fuse box and battery.

Better check the battery as it sure sounds like its dead. The charging system could be at fault also A brand new battery can run down and need a charge if the charging system isnt doing its job Hope this helps you .Good luck!

Ignition switch has a short, same thing happened to me and I went through all the relays and a starter before I found it.

sounds to me like you better find another dealer or possibly an auto electric dealer they should have done it right the first time

sounds like its wired up wrong, remove the radio unplug the connector and remove the radio, then check all your fuses must have blown one when radio was installed, after that charge battery and with radio removed see if battery goes dead, if not recheck wiring to radio, common problem with vw aftermarket radio,they are installed wrong,good luck,

Seems like you've got it under control

You radio's memory and clock will drain the battery if you don't drive this car every few days.

Try going to Autozone or local auto parts store they will check your charging system for free a good battery should not go dead just sitting there ,must be something draining it a light in the trunk or glove box or a radio that doesn't go off or a dome lamp