High humidity

Open the cabinet doors under the vanity and sink and see if the smell is strongest there. There is a good chance one of the air admittance valves have failed. Those valves allow the waste water to drain without sucking the "P" traps empty. Easy change, usually only hand tight. Available at all the big box stores.
Your ACs only recirculate air, they do not bring in outside air.

Richard

stickdog wrote:
Dead skunk in your AC vents?

Yep. Betcha someth'n dun died in there.

Yes and yes on the cleaning the coils. But first pull the ceiling panel and find the four bolts that go up through the roof. Give each bolt about 1/4 to 1/2 turn.

The gasket and AC should not be tightened all the way down to the roof. There is supposed to be a gap that is just filled by the gasket. If you overtighten you will have a leak.

Maybe time to give the AC system a good cleaning. Clean and wash the filter in all your rooftop units, check the drain holes on the units, make sure the gaskets Between the unit and the roof are in good shape and tighten down a bit.

2oldman wrote:
a/c recycles indoor air. It doesn't pull air in.

This^^. Look to your duct system or somewhere else for the problem.

Rob

If it is that "wet dog" small when starting the roof A/C, you need to clean your EVAPORATOR.

Get an evaporator cleaner at any box or HVAC supply store. Cleaning is done from the roof after removing the A/C cover and then the evaporator cover. Be sure to block the opening to the coach interior.

You will be SHOCKED at what you find-- dirt, mold, mildew!

No smell when we are not using AC?

a/c recycles indoor air. It doesn't pull air in.

Go to a rental place and get a small ozone generator. We used to use them to remove smoke odors after a fire or construction odors after a remodeling project. It will not take a big one to get rid of any lingering odors and you can put a cap over the tank vent to minimize odor escape. Be sure to clean the AC filters with soap and water first. You may also want to check the gasket on your toilet to see if the odors are coming in through the toilet. If the bowl will not hold water, the gasket is bad.

Dead skunk in your AC vents?