I have a 2004 f150 xlt with a unknown yellow wire hanging down from above my wheel well on the passenger side. Can someone tell me what this is for or were it goes. I can not find were it came from . Could it be for my driving lights ? They seem to not want to come on unless my headlights are on. or I put my parking lights on . Any help would be greatly appreciated.

 

Your driving lights are ok, that's the way the factory wires them. It's hard to say what the yellow wire is for. I would trace it as far as I could and see where it's leading.