I have a 2005 Jayco hybrid. Last fall, after a heavy rain storm, I noticed there was some black/brown coloured stain on one corner of the A/C (inside the trailer). I popped open the inside cover but c...
Might be dark colored from debris caught up under the A/C cover. Or maybe the roof is just black, coloring the rain water. Tightening the bolts is something good do check on every few years. Did mine last year for the 1st time.