Just Picked up my new trailer but I don't have lights on the inside
#32
#33
Had the same problem with my F350 for years. The fuse controlling it is the trailer battery coil fuse, or may be called trailer accessory fuse, it was very difficult to tell it was even blown. If you pull rvs you may have blown it they draw a lot of amps if their batteries are dead or if you leave frig or lights on in the rv.