I also hate when there's no apparent cause for a blown fuse, but it seems like it does happen. I got my wagon over 10 years ago and a few times it's done that thing where the turn signals stop working but they come back if you toggle the hazard switch. But one time it turned out to be that the fuse blew. That was not long after I got it and it hasn't done it since. It's very difficult to find a problem if it doesn't repeat itself consistently.