Ok this has got me stumped. When you put the nut on the horn and tighten down to the horn cover the horn sound muffled when you push the button. When the horn is not tightened down it sounds fine. Anyone know how to fix this or what might cause this?

 

Don't over tighten the nut, it is warping the horn case and changing the tone.

Just tighten the nut down enough to hold it in place, and use loctite on it..........tighten it until the tone changes.

Steve