If this was a direct short from hot to ground then the fuse would blow the second I put it in but sometimes it might go for a day or two before it goes. This tells me that the faulty wiring or device is somewhere that moves. What I mean is like a door that opens and shuts and wiring in the door might not be shorted until a sudden jar makes it short. Since the circuit controls the right side windows, couldn't it be something in the front or back pass. Door? Where would the closest place be to isolate one or both passenger controls?

I'm also thinking the door because there are some people out there who CANNOT help but slam the door EVERY TIME they get in or out. I would think this has caused similar problems before in a lot of vehicles. Just a thought.

you can grab ahold of the wires and shake them or open and close slam the door and see if it blows