I just hooked mine up last week. there is a horn retainer ring that goes around the outside of that button. That gives it the ground you need .I called Toms and they sent me that retainer ring and explained how it works.
I think I have the retainer ring you speak of. Is it thin sheet metal with a flange that fits into the steering wheel and also has a flange on the top side of the steering wheel?
That's kind of funny about calling Tom's and them explaining. I called Tom's a while back and there were insistent that they never offered a Bronco horn button with just one wire.
If you remember, how did it need to be wired up, and what year is your Bronco? There are horn circuit differences from early to late. Mine is a 69 with no factory horn relay, but I'm using a 78 Bronco tilt column that has two contacts.
Here is Tom's instruction sheet online showing only 2 wire horn button.
http://www.tomsbroncoparts.com/page.../body/66-77-early-bronco-logo-steering-wheel/
The 1 wire needs a relay.
the button has to have 2 points of contact, the other being ground. Thus you only see the one wire.
to wire it with a common 4 pin relay take 12V+ and put that to one side of the coil and to one of the contacts. The other contact goes to the horn. (if using a 5-pin relay then do NOT use the normally closed contact for anything)
Take the 1 remaining wire off the relay (the other side of the coil) and that goes to the horm buttom.
Basic operation is when the horn is pressed, the ground is completed and the coil on the relay energizes. That pulls the contacts together which can then send 12V+ power to the horn.
Is adding a relay the only way to get this horn button to fuction?
I checked continuity on the horn button and the spring clip that most instructions say to cut off is the other half of the circuit. No continuity between the single wire spade and the spring clip until you push the horn button. With no relay, I guess I just need to get the second wire attached to the spring clip without it making contact elsewhere?
