Cleaning the exterior screen on Bathroom exhaust fans

[Scotty B]

Hope I can explain this adequately. We have OEM power exhaust fans in each bathroom. I don't see any brand name inside the rig or on the cover on the roof. The cover allows the fan to run regardless of weather - there is no hatch to open or close.
Noticed a few days ago that most of the air seems to come back into the rig around the perimeter of the inside opening.
I assumed there was some blockage up to on the vents in the exterior cover. Was up on the roof today and the slats in the exterior cover were clear, but there appears to be a screen/filter just inside that looks dirty.
I can't figure out how to get to that screen, though I was mainly up there to trim some branches that ants were using to infest the coach. I probably could have looked harder!
Has anyone else experienced the airflow issue and could you please help me figure it out? This is what they look like from the inside.
Thanks heaps and safe travels!

[Scotty B]

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[Scotty B]

OK, goose eggs on a reply, internet search, and calling the manufacturer - airxcel. The manufacturer suggested I had air flow issues, to contact a tech, and that there was no filter up top. Ha!
So, there is a filter and it is a pain to get too. No access from the roof, you have to remove the four large screws on the initial plate, then remove the four little screws that secure the hood. It pops off and you can access the filter which is like an AC filter.
It was 100% obstructed.
Cleaned it, reinstalled and we're back in business.
I see why all of the posts on this fan are about upgrades, not cleaning.
Couple tips, don't remove the switch, it's a pain to reinstall and is not necessary. Close the drain in your sink so a screw does not end up in your p trap.
Safe travels!

[Scotty B]

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