The horn, lights, power door locks all work independent of the ignition switch, radio and windows are operational only after ignition so that is a vital clue as to is the shift lock detent. If you can get access to the wires at the ignition switch the white wire should have power (12 Volts) key off, if not check for blown 50 Amp fuse fuse #20 in the fuse box in the under hood is bad. Ignition key in the first position white, and black/yellow wire should have power, key in second position white, black/yellow and black/red wire should be live, key in third position white, black/yellow, black/red, should be live and the black/white wire then sends power to the starter relay and on to the starter. But my guess is the 50 Amp fuse #20 is blown.