Any ignition controlled circuit can be affected by a bad ignition switch/harness. The contacts where the harness connects to the vehicle harness get weak and start arcing causing all sorts of odd electrical gremlins. The most common symptoms to first show up are a blinking information center and/or dash lights, key sticking in the ignition and HVAC problems. Since the BCM gets a signal from the switch, it's operation can also be affected. I would have the battery checked first, and make sure all the battery cables are clean before jumping into the switch, but I'm thinking a new ignition switch is in your near future.