If you look at the wiring diagrams posted, you will see that the hazard flasher uses the same wires as the brake lights. So if the flashers work then the wires are good all the way to the steering column. That leaves the stop lamp switch itself or the wires to and from it. I know the OP says they are fine but what else is left? It may even be that the stop lamp switch has been pushed too far away from the brake pedal. There is a round clip on the switch threads that secures the switch. It is adjustable and sometimes it slips letting the switch not make contact with the brake pedal.