Finding my leak

In building leaks they do a smoke test, that is actually a smoking piece of material that you pass over the seams and edges and the smoke will blow when you find the leak. The pressure idea is correct, but not sure if your leaf blower can give it enough force to pressurize the room. You might want to get a thermal camera, put a heater in the room, suck air into the room, and look for cool spots. Might be too many air leaks for this to work. Campers aren't built very well.

I had a leak that showed up in the rear bunk house. Turns out it was from the fridge roof cover. Not sure how it worked its way back to the bunk house, but it did. Had an RV shop fix it and it hasn't leaked since.