rear blinker/ brake ligh out??? HELP
 

I have a 2003 explorer 2 door. and this started out as just my blinker and brake going out, so i replaced the bulb (3157) and it was fine. now 2 weeks and 3 bulbs later i cant get this one blinker to work again. Replaced wire harness and pigtail and even rewired it all the way up to the fuse panel. Anyone got any ideas??