not your typical brake light question

ok so my two rear brake lights are out. the third brake light works and the tail lights work bulbs are all replaced and still no brak lights. all fuses are fine and from looking at all the wiring everything looks fine im not a wiring guy so i have no clue whats goin on and would really rather not have to take it in. please let me know if anyones got any advice

thanks fellas

 

I don't have a wiring diagram on front of me, but the lower brake lights may have a common ground. Try to find out where it is. Look for green fuzzies on any wires as well.

 

Have you done any wire modifications recently?