well from what you are describing is sounds like everything that is powered by the accessory buss failed. Everything that is wired battery direct still works.
Most likely its the ignition switch, the fuse for the circut that actuates the relay that turns the accessory power on and off, or the relay its self.
Get a wiring diagram of the accesssory power circut and check the fuse first. If the fuse is good, turn the ignition key to the on position and check for voltage to the relay exciter terminal. If theres no voltage there and the fuse is good move on and check the ignition switch.
If there is voltage to the relay exciter terminal then ckeck for voltage on the terminal of the relay that is connected to the battery. If there is voltage there, and there is voltage to the relay's exciter terminal then the relay is toasted.
