use a 12 volt test light and have someone mash the brake pedal and see if your getting voltage back to the lights,you could have lost a ground wire or something,but if you can get power to light up the test light when someone mashes the pedal,then it might help you to narrow this one down,also be sure and double check the bulbs,they will look good ,and not be,run a separate power source to them and test them,if that don't work i dunno what to tell you,good luck.