One other thing to check is the battery. This sort of plays into the theroy of too much resistants in our systems. I recently replaced my battery and it solved all sorts of problems. There where no real signs that it needed to be changed, other then sounding weak when cranking in the morning.
When driving in the rain, my Air Bag light would flash a code of 53, which means (I think), the system detects a short in the passenger side circuit. Also, my sunroof would not return to the closed position when the key was turned off. It would mearly close, then open again then close, then open and stay open. There is a funny story to this, but I wont get into this now. Also, the most noteable fix was that when the compressor would kick on, the dash lights would dim quite a bit.
*After typing all this, I wonder why I did not change my battery sooner!*
