I have had an issue with my trailers running lights. The ones that are on when the headlights are put on when its dark. Originally they worked but now not. I have several trailers and this is constant. This leads me to beleive the issue is at the plug on the tow vehicle side. I've checked every single fuse in several locations. To no avail. My wiring seems tight so I'm really at a loss on what exactly is causing this. The tow veh. is a 2003 Dodge Dakota.