my horn died too and i know at least 2 friend with proteges who's horn died the same way. It's pretty stupid the way they mounted it ! A metal unpainted part in the front grill right were all the water, snow and salt gets in !
If youre in a place with bad winters, go change your horn right now !
As for the replacement, pretty much any horn will do the trick so if you have an old junk car sitting around, take its horn and put it to good use !