2005 mustang horn comes on and stays on till it blows the fuse or i pull the fuse 4 times at dealer and still same results they replaced harness, relay back and forth and still it happens anyone else

 

The contact in the steering wheel may be sticking???

 

Looking at the schematic, the horn relays ‘energizing coil' gets it’s power distribution through the Bussed Electrical Center (BEC) and the Smart Junction Box (SJB) controls the ground leg of the relay coil. Unless there is a problem with the clock spring/horn contact, might be a place to look.. Not sure why it would blow the fuse though , since it should handle the load from the horn/s..