Good evening,
I am Piet Keijzers and I live in the Netherlands. I recently bought a 240 Z and am having problems with the mounting of the horn. Here are 2 photos: a photo of how it is mounted on my car and a photo from the internet of how it should be. I don't understand the latter because the small black wire, which carries voltage, then makes continuous contact with the ground, causing the horn to beep continuously.
I will upload some photos of my 240 Z later.

Regards, Piet from the Netherlands.

Edited March 25Mar 25 by keijz

The ring where the wire mounts should not be grounded all of the time. When you press the horn button, the ring makes contact with the steering column that is grounded. What is wrong with your horn is that wire is mounted to one of the 3 screws that holds the ring to the steering column. The mounting screws have insulators to isolate the ring from the steering column. The wire should be connected at the empty hole, and there should be an insulating washer at the screw where the horn wire is currently mounted.

Thanks Steve for your reply.

But my photo wasn't entirely clear, because my wire wasn't connected to the contact plate.

There is voltage on my wire. Is that correct?

So I shouldn't connect that wire to the metal ring.

How does the wire make a ground connection then, when I press the horn?

What you are finding is normal. Here is a simplified view of the circuit.

When that black wire is not in contact with ground, it will show 12 volts to ground. From the positive on the battery to that point, the circuit acts as one long piece of wire. That is what is in the red cloud. Once the black wire comes into contact with ground, the coil in the horn relay is energized and will act as a load.

The black wire should connect to the ring. The ring should not be grounded until the horn button pushes the ring against the steering column. In the attached video, you can hear the horn relay click as I push the ring down into the steering column.

Thank you very much, Steve.

Is my information translating well for you? If not @dutchzcarguy could probably explain it in Dutch.

Steve, I can translate by Google Translate, so it's no problem.

Would you please take another photo of your steering wheel, just like my photo of mine.

Good. I know sometimes technical information doesn't translate well.

Here are a couple of photos. The wire for the horn is attached to the ring at the same point where I drew the arrow in your photo.

Looking at your picture, it looks like you are missing a couple of the insulating washers that go under the metal washers.

I think you are missing the top plate. There should be two metal plates - the black wire should be fastened to the top one. Your picture shows the bottom plate with two large holes. One large hole for the black wire to come through, one large hole for clearance of the screw that fastens the black wire to the top plate. The screw will protrude through the top plate and the large hole prevents contact of the fastener screw with the bottom plate. The top plate wobbles and acts as the switch when the two plates make contact - thus sounding the horn.

Yes, now I understand. I am indeed missing the top plate, as can also be seen in the photo from the internet (my first photo).

Now I have to look for such a top ring.

I'm very glad you helped so well.