My best guess;
Corroded battery to chassis ground.
Corroded battery post : I would have somone start the car while you look at battery, it may spark if poor connection.A large amount of electrical issues can be traced to poor battery -to-ground issues.
let us know what you find out !
Have a safe New Years.
Wife and I are watching 8 grandkids tonite. I hope I live thru it to see 2010.