Brake lights doesn't work, third brake light do work

When the brake pedal is applied the back stoplights (right & left) doesn't turn on, however the third brake light does work. The back hazards and turn signals all work, I even changed out all the back bulbs. I already replaced the fuses, the brake switch on the brake pedal, and the hi-mount stoplamp relay located in the hood and still the back stoplights don't turn except just the third brake light. My next guess is that a wire my be burn't out somewhere and going to the dealer is my last resort if it comes to that. Is there something that I'm missing or I'm not doing right, I'm just lost now.