I had a musty smell inside the coach that came and went. I would use my ozone generator and it would eliminate it for a few days, then it would come back. No leaks, no wet carpet, and it was not coming from the toilet.
Well, it got worse a week or so ago when I turned the A/C unit on for the first time. No doubt about it, it was the A/C.
My brother in law came over and we took the shroud off, and the cover on the evaporator coil. We cleaned the coil with a scented cleaner and rinsed it down with the hose. Boy, there was a lot of crap in there, no wonder it stunk!
I'm not sure how old my A/C unit is, but it appears to be the second unit, as the original screw holes are plugged and we can see the outline of the older unit. I also do not have the right drip pan, and condensate runs down the side.