front and back exterior turn signal not working, dash lights work

I had to replace the turn signal switch because the hazards weren't working. All lights on the dash now work as they should. I replaced the front side marker light, it was blown. Driver signals weren't working outside, Passenger signals worked as should. I replaced front and back turn signal bulb, still nothing.I checked possible fuses, but they seem fine. Checked the sockets, but didn't notice any corrosion.  Not sure where to go with it now?? Any and all will help.