The Stovebolt Site Forums The Shop Area The Electrical Bay non working Horn

need some help / training on how to locate problem on non-working horn.

I tried to locate cause for my non-working horn.
I got to the point of testing the horn itself.

I assume that if I connect a positive power and a ground directly to the two terminals on the horn itself, it will "honk". It didn't!

Am I missing something?

Make sure connections are clean, but it is prolly bad. I have gotten them working again by spraying your favorite solvent in there & letting it soak, then tapping, etc but new horns are too cheap to do that, unless it is a 100 pt. restoration.

What does the horn relay do for a horn? Can I wire directly to the horn without wiring thru the horn relay?

I don't have the wiring diagram for your particular truck, but I can tell you that relays are electromagnetic switches. You have one circuit (low voltage) that switches another circuit (sometimes much higher voltage) on and off. In the case of the horn, the button is probably on the low voltage "switching" circuit, and the horn is probably on a higher voltage circuit.

I'm sure others will chime in, but I would think you should be able to test the horn directly without the relay. I'd think all you'd have to do is disconnect a couple of wires at the relay and touch them together. Doing this would simulate the relay completing the horn circuit in response to pushing the horn button. Definitely look at the wiring diagram for your truck before messing around with anything!

If interested, here is a link that explains how relays work.

The horn relay handles all of the "big" current. They use them so that they can use daintier horn buttons and wiring.

If you do wire straight through, go and buy a starter button for a tractor and wire it to that.

I tested my horn by running a line from the batt terminal on the regulator to the positive side of the horn (the ground was wired straight to the manifold clamp) and it worked very well.

agreed, I ended up finding that my relay was bad , however I was puzzled by the use of a relay as well,,a horn is not a high amperage device, and in my opinion should not need a relay, Ilike the tractor starter button idea

The horn is higher amperage than most of the stuff in the truck and the horn button and wire are not rated for the current the horn draws on vehicles equipt with horn relays. Maybe they went to the relays when dual horns became an option.

I have a horn issue as well. My horn has a single lead wire. It grounds through the housing and bracket. My question has to do with where the single lead attaches (it was unhooked when I got it). Under the hood, I see the voltage regulator, stop/tail fuse block and a relay. The relay has one wire from the BATT terminal on the regulator going to the middle terminal on the relay. A tiny wire leading up through the firewall back to the dash on the right terminal. On the left terminal of the relay looks like a wire running down to the generator. Does the horn connect to this terminal? Or am I totally off the mark on this?

Thanks!

Corey, that sounds right to me. Follow that wire that looks like it's going to the generator, does it actually connect to something? It might be hanging in the breeze, if so, that sounds to me like the horn wire.

CoreyCOE,

I think you hit the bulls-eye. I wouldn't have thought that the third terminal was wired anywhere but to the horn. The generator should only be connected to the voltage regulator.

Stuart

Alright, guys, I haven't tried this out yet but I may have solved the mystery of the extra wire.

According to the 1954 Chevrolet Truck Wiring Diagram that I found here , there is a 12AWG wire that runs from the third terminal down to a terminal block near the driver side head light. This terminal block has four terminals: headlight low beam, headlight high beam and parking light. My horn wire should connect to the fourth terminal.

Thing is, it looks like the horn wire was cut at some point and may not be long enough to reach. So I may have to cut and extend it to reach all the way to the terminal block. Looks like I'll be making another trip to the hardware store...

:rolleyes:

CoreyCOE,

I can't find the wire you describe in the wiring diagram you linked. Is it something specific to the COE models? In the '54 wiring diagram, the wire to the horn terminates near the drivers side headlight...probably on a terminal block, then on to the horn. I'm confused but if you're clear on it, that's all that matters.

Stuart

Atomarc,

From what I could tell on the 54 diagram, the thin horn button wire runs from the horn button on the steering wheel to the horn relay (connects to relay terminal #3). The BATT terminal on the voltage regulator connects to the horn relay using terminal #2. Horn relay terminal #1 shows a wire running from it to a terminal block near the driver side headlight (terminal #4). The horn wire connects to this same terminal on the terminal block.

The odd thing is that my 53 doesn't have a four-terminal block in that spot (just a 3-terminal block for high beam, low beam and parking lights). So I connected my horn wire directly to Terminal #1 on the horn relay. Then I fixed a break in the horn button wire and cleaned up the contact plates of the horn button. I'm back in business now. Beep, beep!!

Thanks everyone!