I believe the interior lights run on the auxillary power plug of the 7 pin. On my 02 it worked fine for about 2 years then suddenly stopped. I figured problem with the trailer......well I finally got around to trying another truck and both a Ford and Dodge hooked up and boom, we have interior lights....We tried a voltage meter on all the pins and the auxillary pin wasn't getting any power so I figured that was the problem, probably a fuse.....but to hook up a new truck and get the same thing is a real bummer.
To answer your question, yes, although I don't know that it would make a difference. Now, all the other lights work as they should, including brake light, turn signals etc......so I'm just stumped......My bro in law was just on a RV site and apparently this has been a problem for others as well so I'm hoping to get some feedback by someone who has seen the same?
I turned the light to the on position thinking maybe the auto-on feature had an effect but I got the same result, no interior lights???