The Stovebolt Site Forums The Shop Area The Electrical Bay Single-wire horn operation?

Hi all. I'm in the process of wiring up my 46 Chevy 2-ton and am now at the the horn. When I bought this truck, it had a single trumpet-style horn mounted to the core-support brace on the passenger side. You can see it here.

It grounds itself to the support rod and used a single hot-wire from a generic push-button mounted on the side of the steering column.

My question is: Is there any way to operate this horn using the stock horn button?

I'm still trying to wrap my head around the stock horn operation as it seems kinda bass akwards to what I'm familiar with.

Should have a relay in that circuit. Check the firewall for a horn relay. If it has one and it's still there and working you can just run a single wire from the relay out to the horn and the steering wheel horn button will work.

Yes it should have had a relay but it didn't come that way.

I have seen a blow-up of it in a manual somewhere. Maybe the Master Parts Book. Are you aware of the Old Car Manual Project?

As Cletis posted, a horn relay was not used until 53 or 54, except when optional/accessory dual horns were installed at the factory.

I had a pair on my '51 that were similar to yours; long trumpet, single wire. Like these guys have stated, there was a relay in the mix. Definitely not original but probably a period correct add-on.

I'm going to use a stock looking relay and gut the inside and put a modern style relay in the inside on mine.

So the stock horn button will operate the horn if I use a relay? OK. I'll try it.

Now riddle me this. There appears to be only a single horn wire inside the steering column, which exits the column down toward the gear box. The other end is soldered to the bearing up toward the steering wheel. Where is this wire supposed to go?

that wire to the bearing supplies the ground for the horn when you depress the horn button, if your horn has a ground at it's mount you will not be able to do what you want, the horn should be isolated from ground internally - if you don't have a wiring diagram, find one here ... use an ohmeter to check the circuit you have now, if there's power to that switch you have a farmer DIY job that is dangerous

Bill

That one wire in the column is the ONLY wire in the circuit. LOL. I pulled every inch of electrical anything out of that truck several months ago. I bought a (modern) harness from Jim Carter and am now starting to re-do everything.

After looking at that diagram and reading a few "tech tips", it appears that column wire (and the bearing it's soldered to) is actually "hot". Depressing the horn button actually grounds the circuit, making the horn toot. horn techtip

Check your diagram again
the column wire is a ground, You get power from another source(maybe ammeter post)

how many terminals are on your horn?

If you decide to use a relay you can wire it like this.

...click...

...click...

I picked up a 12v relay at my local auto parts store.

[quote=DADS50how many terminals are on your horn?
[/quote]

Just one terminal.

Help me to understand. If the column wire is a ground, then where would the power going to the horn button be coming from? I'm not an electrician by the furthest stretch of the imagination but don't I need power-in to the button (basically a momentary switch) then a wire to take that power from the button to the gizmo being switched? Like I said in my opening post, I'm having a hard time wrapping my head around making this work with only one wire gong to (or from) the horn button?

Wire from battery (+) through the ammeter to horn, wire from horn (-) to horn button. When the horn button is pressed it contacts ground and completes the circuit - horn blows. This if for a '38 but yours will be similar. This diagram is for the stock single horn. The accessory horns will need a relay.

Edit, after looking at your picture again I think I see the problem. Someone has mounted half of an accessory horn set as a single horn. The accessory horns have only one wire, a hot wire. They ground through the housing. You have a cobbled together horn set up for sure. If you want to keep the same set-up you'll need to run a hot wire to an accessory two terminal button/switch of some kind then from the other terminal on that button/switch to the horn. I'd strongly recommend you put a fuse in the circuit. This is what the accessory horns normally look like.

Edit #2, an alternative would be to isolate your horn's housing from ground, connect the hot wire from the horn to the battery (fuse in the line), then run a ground wire from the horn's housing to a one terminal horn button/switch. This would likely be the easiest and safest if you want to keep that horn.

Ah. Gotcha. Thanks a million Tiny. I think I like your Edit #2 idea. Isolating the horn from ground then running a ground wire from the horn housing to a switch does seem like the easiest option. Just for giggles, I'm gonna try that with the original horn button. My simple mind is telling me it should work.

Thanks again to everyone else also and for being patient with me. If I can't weld it or beat it with a hammer, it takes a bit for it to sink in!

I'm a latecomer to this thread, but my '53 has horn issues as well. So I should be able to read continuity with my meter from the ring at the top of the steering column to the end of the wire sticking out of the column? If I have nothing, then the wire has become separated from the ring and I should be able to disassemble the column, and should find a broken wire?
ken

welcome to the garage wardkew - not sure what you're calling "the ring", but if you put your ohmmeter from that wire sticking out to a good ground it should show a dead short when you push the horn button, which supplies the ground for the horn[s] .... you don't "disassemble the column" to get the wire out, you pull the mast bearing at the top and as you remove it, the wire should follow along because it's factory attached to it - in fact if you can't pull the wire out the bottom, it's unlikely you have a broken wire - and if you do pull the wire [either way], make sure you tie a piece of string to it so you have something to pull a new wire back thru

Bill