Greetings, I always make sure I sweep of the slide roofs before I run them in. Last night I noticed a black substance around a couple of roof vents. They are at the extreme ends of the coach, right in the middle of the roof. They are about 6" in diameter. It kind of looks like soot from a diesel exhaust.
Has anyone else noticed such a thing? And what are these vents for?
Previous rig 2011 Mountaineer 285RLD, pulled by a 02 Dodge/Cummins Ram 2500 4x4 6 speed...new rig 2019 3120RL.