My brake lights and turn signals work .the strange part is that I just had a brake line go on my truck I replaced it but still the same no running lights when I turn the head lights on no camper tail ...
Some vehicles have the trailer lights on a seperate fuse than the vehicle lights. May have simply blown the fuse. If so, either replace with a known good or check the fuse with a meter. Visual inspection of fuses can only verify it's bad, not that it's good.