Left side brake woes

You would be much better off getting, and studying, a wiring diagram for your car, and using a test light/ohm meter to determine the circuit problem, rather than wasting time looking for an " internal wire" problem or "crossed up wires" !?? You have to know this kind of problem is not going to be fixed by the internet. Sorry, but just my opinion .

I have a wiring diagram for the barracuda but I dont have the turn signal switch diagram