Well my front driverside turn signal works when the blinker is on, but no light is on when the headlights are on yet the passenger side is on. This is the second bulb that this has happened to....I had water in the factory orange lense so I bought new clear lenses, no noticeable water, nothing like the factory ones that were half full of water....so what could be causing this issue....It doesnt really bother me since winter is coming and I loose all interest in keeping my truck looking good till spring but i'm just curious

 

Change the bulb. It's a dual filament bulb and one of the filaments is burned out.