I recently went through this as well. Weep holes on rear window clean and clear, but kept digging and found that the tail lights
were taking on water, and this was running down wires into trailer. Sealed all with butyl tape, drilled a 1/16" hole in bottom of red plastic lens and that was part of it...
I also found that the screws holding the dinette backer board were corroded about 1/2" down the thread. Not willing to take any chances, I replaced those with stainless steel, and put butyl behind plastic washer. Then sealed above screw with pro flex.
Also...took off spare tire nuts and washers and did not like the poor sealing job there. Some sealant here, some there...just too many bald spots. Replaced washers with proflex behind them near trailer wall. Cleaned up and put spare tire back on after drying.
This was of course, after completing a pex water line test to make sure it wasn't the plumbing that was leaking, which a good friend here helped me through the steps and all was well.
Was ready to lose my mind as work is so stressful, fall/winter is approaching and time was my nemesis. If I can be of any help at all with procedures, I would be happy to help a brother or sister out.