Don't know about a recall or draining the battery but there is a micro switch back there that can cause opening problems. See
viewtopic.php?f=5&t=65100&p=717861&hilit=deteant#p717861As to your bcm/battery post:
1. cold is really hard on batteries especially cheap ones. That said if your alternator actually tested good I don't see how the battery could only be at 1/2 charge. Did they test alternator and battery on the vehicle while running?
2. weird electrical problems are often related to a weak battery or bad ground.
3. I'm not up on all the details, a google search would probably help you but the volt meter in the fuse box test (don't forget the power distribution center fuses - at least I assume an 04 has them) is to check each fuse to see which ones are powered on with the ignition off and how much the power draw is. There are a few circuits that dribble a bit of power with the ignition off to keep things like the radio clock working but that power draw is so small it won't drain a battery in any less than months.
I would not recommend going to a dealer to hunt for an electrical problem unless you really know the dealer. An independent auto electric shop is probably your best bet. In fact that's where the dealer's here send the problems they cannot figure out. Over the years I've experienced battery drain due to a) a glove box light that was always on; b) a short in the trailer light harness that had somehow come loose and dragged on the road; c) a problem with the passenger seat air bag sensor module.