I try not to drive our M.H. in the dark, we try and fine a place before 5:00 P.M. to stop for the night.
You might want to try and clean the Len's after all your Rig is over 12 years old
so is mine.
About the only time we use our lights is when we are traveling in the rain and only if a large truck passes us on the road and when he gets far enough in front of me I flash my head light to let him or her know that it O.K. to cut in front of me.
Just a thought.