OK, got one out and apart. Something doesn't make sense to me. When I apply juice, the "plate" is drawn down to the coil, the thump. Remove juice and it returns, click. What I don't understand, the contact on top. The way it is now it does not do anything that I can tell. It is open as you can see. When the plate moves down when juice is applied, it just opens wider. Suggestion????

I am NOT an expert BUT as I noted before I had the same issue after putting mine back together. If you look at the picture below you'll see the guts of one of the accessory horns in three pieces toward the bottom of the picture. The piece on the right is the vibrating assembly. The large metal, silver colored round part you see is the diaphragm that does the vibrating. When I first put my horns back together I got that put in backward. It's designed to be pulled to one side by an electromagnet when you complete the circuit by pushing the horn button. When it gets to that side it makes a contact which kills the power to the electromagnet, causing the diaphragm to swing the other way. As soon as the diaphragm moves away from the contact it repowers the electromagnet that then draws the diaphragm back to the contact. This happens very fast, causing the vibration of the diaphragm that is heard as the horn "honking".

When I put mine back together I had the diaphragm 180 deg out so that when I pushed the horn button it would be pulled to the electromagnet causing the "thump" you describe BUT the small protrusion on the diaphragm that was supposed to make contact, killing the power to the electromagnet never made that contact so it never vibrated. When I finally figured out what I did and put the diaphragm in the correct orientation they worked great.

I suspect you horns are doing the same thing. The part that actually makes the noise is not what you have marked as the "plate". You can see a tiny bit of your diaphragm through the hole just above the the "E" in PLATE. Remove your vibrating assembly and look closely at your diaphragm to see if there isn't a small contact stud on the magnet side that doesn't make contact with anything. If so a repositioning may solve your problem like it solved mine. Maybe someone who IS an expert can be more specific. I don't have better images than the one below so I hope it helps.

Could not stand it any longer. Took it apart as far as I could. Put it back together and adjusted until the contact on top just touched with slight pressure and, drum roll, honk honk! What a beautiful sound. One down, one to go.

Tiny, I tryed fliping the vib disk over but it would not go back together. Thanks for your help.

Glad you got it working. BTW I didn't flip mine over, just spun it 180 deg like turning a record on a turn table. It seems when I put it back together the first time I mis-positioned it.

Tiny, on mine it will only fit but one way because of the notch where the power wire entered. I was just trying anything I could think of.

They must have had too many bozos like me putting things together backward so they made newer horns where they only go together one way. Glad you got them working.

Russ, glad you got things honking...

Found my old horns in the barn this mornning.....they still work. Finally got the cover off one of them and the points are touching with no power applied. Here's a couple of pics....





Firs time that one has ever had the cover off.

Honk Honk

Glad you got yours working.

Hey Tiny, after looking at all the info on the trumpet horns here, I went out and got mine to work a little bit. What I mean by that is, after I adjusted the contact points they had a dull honk sound to them. Did you find a place where the volume can be increased on these? Many Thanks to all for the info on this.
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Joes 37

Hi there,
I have several 6 volt old horns and would like to test them for working, and later fit one to my car.

At the moment I do not have any type of 6 volt battery and wonder if I did a temporary set-up and activated them with a 12 VOLT battery, WOULD it damage the internals and make them total scrap, IN AN INSTANT???

Peter

The only adjustment I know of is in the center of the diaphragm. You'll have to unscrew the trumpet to get access. I didn't fiddle with that on mine so I'm kind of shooting in the dark here.

Thanks Tiny. I'll have to check on that the next time the temps. get into the 30 deg. range agin.
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Joes 37

Joe this was my first time inside a horn. What I can tell you is it took a good number of adjustments before I got it to sound right. I would turn the large nut 1/12 turn at a time. Even them, when I was sure I had it, after I tighten the jam nut it would change the tone/loudness. Many times it would sound as you describe. Then turn alittle more and it would get louder or softer. When the points were just right their was a really nice blue spark (like a arc weld) between the points. Just my experience.

Peter. I was in the same boat. I did not have a 6 volt battery either and that's why I did not test before installing. Like you, worried about using 12 volt. Maybe someone will come along soon and answer your question.

"DITTO" on everything you did Russ. I would have them sounding nice before I tightened up the jam nut. That,s why I wondered if there was another adjustment. Thanks agin,
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Joes 37

You can give the horns a quick test with 12-volt. A quick check and no harm, no foul!

12 volts MAY change the tone but will confirm correct operation at least.
Tony

hi there Tony,
I have a 12 volt battery charger and wonder if there is some type of resistor or other that I can insert between the cables so that the charger will work at only 6 volts?

Or do I have to buy a bespoke 6 volt battery charger to maintain a 6 volt battery?

I would like my horn to sound original and not 12volted...

Ohh the pain of it all..............

A cheats way to reduce voltage is to connect 2 items in a daisy chain arrangement (a headlight globe) and the horn may work but the globe may not allow enough current but will reduce the voltage. If 1 dont work neither will work.
Tony

Hm If you have two 6 volt horns and a 12 volt system try to wire the 2 horns in line more chance that they will work fine.I have 2 in my Fleetmaster but as the car is still 6 volt I never had the need to try it myself.
If someone gives it a try let us know the results

Jianis

While wiring two or more items in series will result in a voltage drop the amount of the drop depends on the resistance of the items. V=IR As you increase the resistance the voltage drops.

I know all that but as it concerns vibrating coils, witch means the resistance of each horn will be between zero and maximum at any given moment, it is better to just try it and see if it works

Jianis

In the case of a horn activated by an electromagnet, I would expect that each horn would be drawing current ~ 1/2 the time. Don't know the cycle time but the frequency of the horn would give it to you if you had a tuned ear or other measuring device. Just try it is likely the best option. Definitely the most expedient.

There is a high and a low tone horn in a pair.
My guess is that the high tone one is vibrating in a higher frequency as the low tone one, but I can also be mistaken,the high or low tone can be achieved by using diaphragms of different diameters or using a different acoustic chamber.
In this case if the two horns are connected in line the 2 coils will only be able to vibrate on exactly the same frequency with only a fraction of a hertz difference of each other that is because both contact points have to be in the closed position at the same time for electricity to flow.This way the frequency will be what the low tone horn one can obtain.
If both coils have the same resistance then they will also have the same Voltage or do I see it wrong?

Jianis

hi there,
I have just made a bracket and fitted a horn to my 34 chev, just forward of the carbie, attached via the 2 forward inlet manifold bolts, which seems to be a popular position for Horns?

The wiring loom instructions say connect wire K to the horn, and the other to the steering column connection wire.

Question: what goes on the other terminal on the horn?
it it an earth or just nothing?

installing this loom is becoming a nightmare, no knowledge is a hindrance at the moment............

Peter

Peter
1 of the wires goes from the back of the headlight switch (I think) to 1 of the horn connections the other horn connection goes to the wire that goes up the steering column (mast) to the button on the steer wheel.
Tony

The wire to the steering column is the ground wire. The other terminal is connected to a power source. When you push the horn button you are making the ground connection, completing the circuit and honking the horn.

I'd be very surprised if connecting two horns in series worked. It doesn't work the same way as lights, for example. If you connected two 6 V headlights in series to a 12 V battery, each one would have 6 volts across it because the resistance of each one is approximately equal. But the horns are constantly interrupting the current and they don't act like resistors. So the simple V = IR law doesn't apply. To complicate things even more, each one is interrupting the current at its own rate (frequency) so it would be tough to keep them both happy.

The good news is that horns are very forgiving and hooking one to a 12 V battery won't hurt it, provided you just "toot" it and not sustain long blasts. I have a friend who converted his '54 pickup to 12 V and didn't change the horns. The pitch changed a little but the best thing is that they got even louder than they were originally!

hi Tony,
On looking at the wiring diagram, what you say now makes sense to me.

Question: Does it matter which terminal on the horn, the wires are attached to? are they universal, power in and out?

Peter

It does not make any difference which one each wire is connected.

Can someone shed a little light on which wire go's where on the 6 volt horn relay for the trumpets? I'm thinking my relay might be shot. Thanks for any info on this,
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Joes 37

Yesterday I did a test on the 6 volt horn, it worked.
I was not prepared for the very loud noise that it made and it made me jump in the air, 2nd and 3rd test I had regained my composure

Do I have to wire it up with a relay and if it is advisable, do I ask for a 6 volt relay?

Peter

The single horn doesn't need a relay.

...It never dawned on me to change the horn when converting to 12 volt...and I didn't notice a difference...