Figured it out.
I check the junction boxes and didn't find anything. At this point I was going to point to the campground. Until I got a jolt setting up the sewer hose on our second day into a two week trip. I discovered that the 120v line out to the slider would occasionally hang low enough to make contact with the tire. After turning off the power and closer inspection I found three spots where it had rubbed.
After spending 15 minutes splicing out the bad section, I figured out how it happened. The plastic bracket that holds the electrical lines out to the slider attach the lines with three "clips". These clips are aloud to slide along the bracket. When I slide two to one end and the other to the other end the middle hangs down about six to eight inches, which makes it low enough to make contact with a tire.
Going to call the dealer today to see if I can get a new line put in under warranty.