Is the magneto horn a one pole or two or can be both depending upon who made it or when?
I know there are two different types of mag horns, one is the pyramidal rear can and the other is a small cylindrical can (looks sort of like a top hat with a really large brim). The both house two coils that from what I can figure, work against a platen that screws into the diaphragm, pretty much like how the points work on a buzz coil, which I guess the horn really is, only it has a diaphragm to intensify the buzz noise.
If any of you have pictures of your units disassembled I would appreciate seeing them.
Also the later models electric horn, large can and I think has two post on it, one is hot and the other ground right? What makes the noise in it? A motor I'm sure but what beats against the diaphragm a spur wheel contacting a button on the diaphragm like in the Spartans? Would also like to see one of those disassembled too...if anybodies got one or two or three, lol.
Only one contact, positive terminal on horn, negative ground by bracket to motor mount.
This is a buzz horn, not motor, no spur wheel. Electro magnet rattles the diaphragm.
Have both with top hat cans
I know one term horn used a single bolt mount on metal firewall and the two bolt mount horn had two terminal for he wood firewall cars
Now i have not confirmed this but everyone i have asked say it this way
Been a long time since I fooled with a magneto powered horn. IF I remember correctly, they came both in one and two post versions. Remember, all '15/'16/'17 horns grounded through the horn button directly to the steering column. That by necessity means the power must go to the horn first, then out to the horn button with the single wire through the small tube up the column to the button. That can only be done with two posts on the horn. One, power in, one to ground through the horn button.
Along about sometime in 1918, Ford went to the combination horn/light switch, which ran power through the born button and then grounded through the horn. What I am not sure of, is when did Ford move the horn from the wooden firewall, to an engine mounted bracket. I believe there was an interim grounding through the horn to the steering column and firewall bracket, but am not sure about that. I think (don't think, its bad for the brain) they went to the engine mount about 1919, and grounded directly through the horn internally, which only required one post (power in from the horn button). I have seen a few Ts with firewall mounted horns using a short jumper wire from the second post on the horn to the firewall bracket. But I don't know if that was original or not.
Hope something there helps.
Dan, looks like the diaphragm is riveted to that motor mounting plate on the electric buzz horn, or have I got the wrong idea there?
Also the plate/bar on the back of the motor, is that a spring? The motor energizes pull the beater from the diaphragm and the spring pushes it back breaking the circuit or visa-versa? Is there a button on the diaphragm itself, that the "beater" post in the motor hits against? Is it adjustable from the mouth side of the horn bell for tone or volume, with a screw slot and a jam nut?
It would figure that an electric horn would ground through its mounting if mounted on the engine, but would require a ground contact or just one of the bolts that hold the bell to the horn body as a ground on a firewall configuration.
Wayne...if the two post mag horn runs one wire down to the horn through the tube on the bottom of the steering column, from what I've seen that tube is pretty darn small (one wire capacity only)...why not just run the ground wire to a steering column mounting bolt on the firewall, since the horn button is already grounded to the steering column tube and the whole assembly to the front axle and frame?
How would the single post run a ground? From the horn mounting bolts to someplace on the engine or frame?
I don't have one of these horns, I've got a hand Klaxon, I know how it works and how the Model A electric Spartan works as well...but these buzz horns...I'm sure they're simple, but I really need to understand their workings to get them right.