Condensate not draining. Codes E7

[Matt Kline]

Our Dometic AC was replaced at AS Boise in 2019. Technician said he was having trouble connecting condensate drain. It worked pretty well for quite a while but recently started coding out.
Sometimes it drains, sometimes it doesn't. We try different level placements but it's hit or miss. After it dries out the AC works again, sometimes for weeks, then it fails to drain properly again. We have repositioned the trailer when it's not draining. Sometimes this works, sometimes it doesn't.
How do I simply allow it to drain onto the roof? When it works properly, the condensate drips down by the front axle. I can't find photos or diagrams to know if I have a pan or what is up there to channel condensate.
We bought out 2010 FC 23FB new, and it has at least 100,000 miles now. If I remove the cover, will it be obvious how it is SUPPOSED TO DRAIN.
I am no mechanic, but tackle jobs I can find instructions for. Replaced water heater, and furnace myself. I haven't found any threads with my issue.
Any help will be appreciated.

[Wazbro]

I think your trailer would have come from factory with a drain pan, since the tech was having trouble connecting the condensate drain it was probably changed to drain cups.
You would probably need to take the interior parts off to see how it is set up.
Many of the older AC units would keep working and just leek into the trailer when they stop draining properly.