I feel that it’s definitely something going on with the trailer connector, as I hooked them up to another truck and they worked fine. Is the TRM accessible? Does anyone know where it is?
UPDATE: 10/22
Trailer running lights issue was solved by replacing # 25 fuse, located in slot 71 in the lower fuse box, under the hood.
There seems to be a confusing info on here about the factory installed tow packages TRailer Module. The trailer power connector still has a fuse that can blow...