has a dead miss to it and blinkers wont work

has a dead miss to it and blinkers wont work I habe a 2004 ford mustang base body 3.8 v6 car run and everything just has a dead miss to it and blinkers wont work i replaced the coil pack what would i do next and i replaces blinker flasher fuses and the relay but blinkers come on but wont flash can some one help please