Your picture is too small to be of any help. The horn button is the ground. The S wire is supposed to make contact with the side(s) of the hole(s) in the steering wheel while, at the same time, making contact with the copper strip on top of the steering mast bushing. This contact completes the ground and honks the horn.

Put the steering wheel on the mast, remove the S wire from the rubber bushing and slide the S wire through the holes until it makes contact with the bushing while also touching the side of the hole(s) the legs of the S wire pass through. That should cause the horn to blow. If you have to wiggle the S wire around to complete the circuit and honk the horn, your contacts on the bushing and/or the edges of the S wire holes are dirty and preventing the contacts from touching. That whole set-up is problematic. There was a period accessory one could buy the consisted of a small metal plate with ears that connected to the S wire and a small spring on the flat of the piece of metal. The spring would ride against the top of the steering mast and would make more positive contact when the horn button is pressed (not depending so much on the sides of the S wire making contact with the sides of the holes). I suspect one or more of the contact points is dirty/corroded and preventing the circuit from closing.

Here are a couple of new pictures hope this helps.

Hello Michael McDonald,

Tiny has you covered with his post. Here is what i'll try and add. Your horn button test without the steering wheel installed, must have had a ground that you provided for the test, i'm thinking. Then, when the steering wheel was installed, the test failed. You should shine-up every potential ground as advised. Don't forget to clean the mast bushing contact surface also. Consider, maybe the distance between mast bushing and steering wheel could be too far apart for horn button legs to make contact. Don't know, just a guess. Check out VCCA old forum: (title) How Does The Horn Button Work? by Bare Feet 12/01/16 02:33pm #379599.

Link to the thread.

FWIW I added about a 1/16" of solder to the ends of the legs on my S wire so I don't have to push the button in so far to make the horn honk. I started with 1/8" and ended up taking some off to get it "just right".

I did use a ground wire the first time with the wheel and horn button off. It was the woodruff key it fell in the gap. After we removed it we used a ground wire.

I will clean everything and see if I can make it work.

Thanks again for all your help. After removing the steering wheel several times and cleaning and sanding I finally got the horn to work. Now I guess you can say I can toot my own horn.