roof leak detection

[BoulderB]

Hi all, I have a 2015 Jayflight SLX camper that lives outside. I recently noticed on the inside that the front left wall was swelling, it turns out water has been leaking in and rotting the plywood. I took off the air conditioner cover on the roof and noticed these two spots on the roof where I think water/snow has been pooling up and leaking in between the sheet metal and the interior (see attached photo). I am going to use some Dicor caulking today to close those up and see if that fixes the problem. The only way I could think of checking it is to use some red food coloring after the caulking is dry, then maybe stuff some paper towels in the opening of the wall inside the camper to see if water is still leaking in and if it's colored red, indicating that the leak is still active. Any better suggestions or other things I should think about? Thanks so much in advance. Photo is in my next message below.
Bill

 

[BoulderB]

Here is the photo: https://drive.google.com/file/d/1GRgFT7XpVP8__5SzoQlUWmEdhzN2XTZC/view?usp=share_link

 

[Glamper64]

I wouldn't bother with the red dye...you should cut out the rotten ply on a stud to see if leaking after you Dicor...probably some wet insulation there as well that should also be removed. Repairing the wall/ceiling after is another issue...patch with same thickness plywood and maybe wallpaper over that entire wall...make like an accent wall, or wallpaper the whole room