I have been blowing the incab fuse (15 amp) to the tail and corner lights (essentially the parking lights. Brake lights and directional are unaffected. It only blows while moving, so I assume it's a grounded wire that only contacts while moving. It doesn't matter if the parking lights are one or the headlights. I have replaced the headlight switch, disconnected the tag lights, and tugged on every wire I could reach. I welcome any recommendations, as this has been going on for a while. My next step is replace the fuse with a paperclip and see where the fire starts.