I have tried connecting a trailer to my truck and have had some issues with the lighting. I can get turn signals/brake lights to work, but running lights will not work. Any ideas??

 

Headlights on? I put my boat away for the winter, so I'm only going by recall, but I think I had to use the second last setting on the headlight switch (picture of the headlight). For some reason, I think when I turned to the last setting on the headlight switch, running lights went out. Then again my emergency brake may have been on parked in the driveway. That may have kept them from coming on.

 

^^^^^^This^^^^^^

 

my friends did the same thing and there was a bad relay under the hood. ford knows about it. when i bought my truck there was a new relay already in the driver door. quick fix