ZEEK

So couple of days ago my horn stopped working, i decided to look in the fuse box under the hood, the fuse box by the steering wheel and the one in the trunk, i couldnt find anything then i called MB and they told me they call the horn "fanfare" so i finally found it under the hood and changed it. My horn worked for a day or two and then the fuse burned out again? Does anybody know why my horn/fanfare fuse keeps on blowing out? Thank you very much guys...