Do you have weird rattles coming from the roof of your RV when the Air Conditioning is running. The cause may be that the AC units mounting bolts are loose.
Manufacturers oftentimes reinforce the roof under the sheathing to provide secure mounting for rooftop air conditioning equipment. If you look closely, you will see where Newmar installed aluminum sheets under the sheathing to reinforce the roof on my 04′ 4010 Newmar Dutch Star.
Prior to my replacing the roof shown in the photo taken the summer of 2018 I had a rattling problem. I checked inside the AC unit for wasp nests, loose metal parts, and loose screws. I’d put it back together and it was running and rattling when I leaned on it to get up off the roof and the rattling stopped. So I decided to tighten the mounting bolts.
Mine were covered with silicone, and that was a pain to pick off, but I tightened up the mounting bolts, and voila the rattle stopped. Be careful to not overtighten the bolts and be sure to replace the silicone.