Most all of the horn rings are insulated from ground and only tightened to the point to have a slight separation from ground source..it is as mentioned earlier that this can be over tightened or insulator missing or ever further, insulation in place but with a slight misaligment..break/tear allowing contact. The horn need to be adjusted with the ohm meter or at least muzzle the horn to keep neighbors ears protected while you trouble shoot. If this gap is not correct and even around the mounting/insulated point it can cause ease of blowing from one angle only and this is what in turn creates excess pressure that ultimately breaks horn ring as a owner tried to blow the horn..these assemblies are not just bolted together..they are assembled and adjusted..