How to go about fixing skylight leak

CA Traveler wrote:
Water can easily trave 3' and more before its detected. Repair and then check for leaks including tilting the RV. Check while in storge after rains.

Thanks. Makes sense and helps.

Hearing that the water can travel before leaking into the RV increases my confidence I may be on the right track.

I dug further today and did find something very suspect. I pulled off the caulk around the suspect spot I talked about in my original post, which is the fantastic fan. It turns out that the edges and especially the corners don't lay flat on the roof. Especially one corner is warped upwards enough that there is a gap under the corner. I can't say if it was always warped like this. It could very well be that this warp pulled the caulk away from the roof enough for water to go under.

Today I removed the old caulk. Tomorrow I will re-caulk. Then after it dries I will do as you say, check for leaks. Take a hose up to the roof again and see if I can get a leak.

This doesn't prove I found the problem. There could be several other spots also about to leak. I was in the middle of a full re-caulk when this happened (unfinished before my last trip because I ran out of caulk). The suspect fan is one of the places I had not re-caulked yet. I am surprised because I have be assuming that the current re-caulk is only preventative maintenance, because the old caulk is getting old and was still adhering. Hopefully there is a real problem in only this one place because the plastic on the corner of the fan has warped.