This is what I do, and I'm not sure what thread size is in that knob but I had a hard time finding it.
I, too, have seen the 'horn spontaneously blaring', and I also know that things like relays and breakers can fail and short at any time.
Total side note: Buy a flir camera for your cell phone and go over your harness, car off and cold, and after a drive. It's cheap insurance and if you see that hot spot...FIX IT
