Turn signals wont work, all other lights work. turn signals wont turn on. 1984 Military Chevy Blazer

The element are serpent in the lights bulb the turn signal and brake usually share the same one but the running or park light are not shared with the turn . so if none of the light for the turn signal light then you will want to look for your flasher control it is ether in or near the fuse box or under dash by steering wheel shaft,,you should also check grounds at light socket if we can be of any further assistance please feel free to ask hope this gives you a place to start .Thank You..