Classic Mini or new MINI? The new MINI (2002 and newer) uses dual horns - one one each side. One is a high note and the other a low note. If one fails (and sometimes they do, one of mine did), then the sound is diminished. These horns use a specific plug arrangement and so you do end up having to get a replacement from a dealer. The trick is figuring out which one you need, the right or the left. If you stand right in front of each side wheile an assistant briefly presses the horn button, you may be able to tell which one has failed. Another way is to disconnect one side and and see if the other sounds when the horn button is pressed. They are kind of hard to reach, but loosening the bumper cover at each corner will give room for smaller hands to reach in and remove the horn.

I have a loud high note horn if you need one. (single wire)

Mark Looman, Ada Michigan 1967 Austin Cooper S

Try it with a direct wire to the battery. If the loudness returns then it is the horn electrical circuit building up too much resistance. You can wire in a relay with a direct wire to the battery (starter solenoid) and have the horn circuit activate the relay.

My horn recently "died"  it used to be quite loud, something i liked, but now it sounds like a clown car horn, like it's operating at half power.  anyone ever had this problem or have suggestions as to what might be causing it?  do horns wear out?  should i bother fixing or just buy and install the dual airhorns from minimania? 

 please help.