I've had the same problem as others with my Sentra. In fact, my horn just blew around 58,000 miles. It's also not a fuse.
The interior integrity of the car is awful. My visor mirror cover snapped off in year 3, and I rarely use it. The upper console holding the map lights and the sunroof switch hangs down from the roof. When you close my back passenger doors, the inside handles pop out.
Also, if I start my car and move it a little bit, like out of someone's way, and then turn it off, I can't restart the car.
My favorite problem is the brakes--sometimes they work well, sometimes they don't, especially if it's wet outside.
Yes, you sure found that out! You are not the first one to suffer the idiosyncratic Nissan. Next time, get a Corolla. You won't be disappointed.