[tentcamper]

There is so much going on in that location. The AC, roof vent, and the top roof epoxy roof seam. I assume you have replaced AC / roof seal gasket?

Do you store it out side? If so I would try taping off a garbage bag around the AC unit to the base for the AC, and check it after a hard rain. I have also heard of people using a garden hose to try to isolate a leak.

On an old camper I had. It took awhile to find the leak. It was a rivet in the roof vent cover. But looking at my TM, if the rivet leaked it would not leak inside. One of my campers when it rained hard or driven in the rain it would splash up and leak in a spot that the foam seal was missing between the cover and base of the vent.

What a PIA leaks are?