Dual horns - Wiring
 

I bought these horns at a anitque shop. I don't think they are Ford, but they look like what is supposed to be stock on my 41. I need help with the wiring and operation of these. My one big question is how they are supposed to work. There are contactors that look like points in a way. Is there supposed to be a gap between them? Is the metal holding the points spring or is it the kind that bends when it gets hot? I tried attaching pictures, but it wasn't working.

Re: Dual horns - Wiring
 

The files were too large. Here they are.

Re: Dual horns - Wiring
 

Ford did have dual tone trumpet type horns back in the day but a lot of others did too.

Re: Dual horns - Wiring
 

I suspect a 41 has horns like a 40 in which a relay gets power , both horns have a single wire to the relay, there is also a ground wire that goes to the horn button that makes the relay close the circuit and honk the horns. A relay is a remote switch to handle the heavier current then what you want the switch (horn button) to carry.

Re: Dual horns - Wiring
 

The points should open and shut with the vibration of the centre shaft ,you may have a nut missing that sets the points on the small centre shaft ,this is set close and you tune it according to the tone you require .the wire that exists can be attached to your battery with a wire to the body for ground.

Re: Dual horns - Wiring
 

They are a basic vibrator coil. Power pulls the armature that manipulates the diaphragm til it contacts the points insulated actuator tab and breaks the circuit then it rapidly moves to continue the process. This creates a vibrating oscillation that makes rapidly moving diaphragm emit the tone. The armatures have a set air gap (different set ups may have different air gaps). The diaphragm generally has a tension adjustment to get the smoothest tone. A person has to play with that some to see how it acts but keep in mid that it was originally preset so adjustment is usually not necessary. Points can get crusty over time and would need a clean up. If the coil is still good (has continuity with an ohms reading) then it should still work as long as the points and armature are still working properly. The diaphragms can crack so a person should inspect them too.

Re: Dual horns - Wiring
 

Thanks FlatheadTed and Rotorwrench. That is what I was wondering. So at rest with no power, there should be a gap between those points? There were two nuts on the stud. I am just trying to figure out how these are supposed to look. There was a large nut near the base and a smaller nut towards the top of the stud. Do these act as limiters to how much the points vibrate? I'm hoping I can get this figured out and run these horns. I love the way these old horns sound.

Re: Dual horns - Wiring
 

The points should be firmly mounted as the coil is. The armature is the inner shaft that moves inside the electromagnet.

It looks like yours are missing the nuts & locknuts that open the points. Check this cut away. It looks similar to yours but has a different projecter cone.
http://navyaviation.tpub.com/14329/F...-Horn-311.html

Here is a GM type but there are similarities with all vibrator types.
https://www.hometownbuick.com/1952-buick-signal-system/

Re: Dual horns - Wiring
 

There should not be a gap between the points at idle. The contacts are used to close the circuit so the electromagnet pulls the diaphram down. The missing nut then pulls the lower points bridge down, opening the circuit which then moves the diaphram and the point bridge up to close the circuit again. Then the cycle continues. The second nut locks the first nut in place. The time which the points are closed under power is one factor in the tone.

You need to test with a high amperage source of power (like a 6 volt battery). Ground the horn base and apply power to the lead. Move the big nut down until you get the proper vibrating frequency (good tone). Then lock the nut with the second nut. If the diaphram does not move with power and the points closed, clean the points and try again. If the coil still does not pull, apply power to the lower points (bypassing the points) and see if the coil works. If not you have a coil/circuit problem.

Re: Dual horns - Wiring
 

I had points & armature mixed. The air gap is for the armature. Sometimes metal bits will get in there and keep the armature from moving properly. The point gap has to be adjusted by current draw. But they should be closed when the coil is at rest and no power applied. The breaker points gap regulates the oscillation distance. Most manufacturers have info about adjustments but I'd have to do some digging to see if I have any instructions for Ford types. I'm sure there were several manufacturers of them but I don't know about the trumpet types. They were used in the 40s but I can't remember the applications. All I could find was that they draw 24 to 28 amps total with dual horns.