Yeah, stereo and such... But that's been there for years. The newest addition is a backup camera, but that's also been there for over 2 years.
The "auxiliary power" fuse is for the cigarette lighter plugs, which is exactly what the backup camera plugs into, but I've only recently hooked that up. Even so, I usually leave it off because it's wireless and seems to interfere with the keyless entry. Then after I get in the truck, I turn it on so the backup cam turns on.
So... the small drain I saw could be explained by the backup cam... But again, it's been there for several years and always gets shut off anyways. In fact, it was disconnected completely because I accidentally broke off the camera. I hooked it back up after soldering and repairing it, but this battery drain problem has been going on much longer, during the time the cam was disconnected.
So if that's all the draw was, I'm back to square one, as I didn't register any draw when I first had this problem (while the camera was disconnected).
On top of everything, I got a sweet battery light after starting the truck up today. That was never there before. The only thing different about this time was that I removed the alternator to have it tested. I had a difficult time getting the control plug harness out, so I might damaged a cable in the plug or something. I'll have to look at that tomorrow.