I took mine appart due to almost no sound - cleaned dirt and rust from them and resprayed with black paint. Went over the eletrics and made shure there was a good connection. They both worked 100% when I put them together again. You can also get new ones, SLS have them for about €60 each, but since this is fairly simple electronics you should be able to make them work again. Check with a ohm meter that the solonids are working. Also remember that this is a two tone horns, each marked with the individual frequency.
Kjell
Sl 280
Norway