The horn spring meltdowns occur because on the AD design trucks many do not use horn relays. There is power to both sides of the horn and it grounds at the steering wheel. Many horn contacts in the steering wheel purchased thru suppliers only have the contact with a small spring in it without the braided wire that it needs to carry the extra voltage. Thus the small spring melts inside the horn contact case. I took apart a contact purchased from Jim Carter and soldered my own wire inside. Everything works fine.