Hutchins ah-oo-gah Horn Wiring Diagram

[kcav8or]

I'm trying to get my Model A's Hutchins ah-oo-gah horn working again. Does anyone have a wiring diagram for these horns? There are two coils outside the rotor. One has two wires connected to one of the brushes, while the other has two loose wires that apparently contact the case and vehicle ground. There are also two wires. I assume that the better-insulated one is the negative, non-ground wire, and the other is the positive ground.

I'd appreciate comments from anyone who has done this. I can't find much detail on these horns.

[Mike V. Florida]

the model A horn does not have a connection to ground inside the the horn. The ground for the horn is from the horn button.

If the Hutchins horn does have a connection to ground you will either need to to install another horn button to supply the voltage or you will need to wire in a relay.

The standard model A horn, if I remember correctly, should be wired "in series" that is one wire goes to one of the coils then a brush through the armature to the other brush to the other coil and out.

While this picture from Tom does not have the brushed installed it should give you an idea of how the Model A horn is wired. Do you have pictures of yours?

[Tom Wesenberg]

Can you post a picture of the inside of the horn?
Some horns use a frame ground and switch the power going to the horn.
Model A's have full time power and ground through the horn button.

Model A's have the power run through one field coil, then the armature and out through the other field coil to the horn button for grounding. The fields and armature are in series, so it doesn't matter which terminal get the power, and which leads to the ground.

In my picture above you can see a mark in the left brush holder. That is from someone using the wrong screw (too long) and running it into the holder and bending it, which locked the brush in place.

[kcav8or]

Here's a picture of the horn. You can see the two wires and the loose armature writes on the left side, which I must assume were grounded to the case.

[kcav8or]

When I opened up the horn, the rotor was frozen in place. I started taking it apart, and saw that the clip on the back that contacts the axle of the rotor had a bunch of black, powdery stuff around it, which I thought was some disintegrated rubber. But when I started removing it, there was a hard core. I got out the Dremel to remove what was left and discovered that it was actually copper under all that black, powdery material. After I cut that away, the rotor was able to move again, so it had apparently seized up at some point in the past.

[kcav8or]

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Sorry, looks like the picture didn't upload the first time. Here it is. Again, the loose wires on the left side puzzle me.

I've also included a picture of the coils and how they connect to the brushes and wires. The coil on the right makes sense to me. One end connects to the power lead, and the other to the brush. I would expect the other coil to follow the same pattern. But it doesn't. The power lead is connected directly to the brush, and the coil is wound differently. It appears that two wires are wound in opposite directions, and twisted together at one end.

[Tom Wesenberg]

Someone bypassed one field coil, probably to run a 12 volt horn on 6 volts.
I've seen one field ground out on the model A horn and it still worked OK except it blew constant, rather than the horn button supplying the ground.

[kcav8or]

Interesting. The label is very faded, but I can read that it says 6 volts. So maybe that was done by the manufacturer to reduce production costs. Should I rewire it the same way, or can I bring that other coil into action?

[Tom Wesenberg]

If you put the other coil in series, like the Model A horn, then make sure the coil isn't shorted to ground and make sure the correct wire goes to the brush so you don't get the wrong polarity. One coil gives a north pole and the other a south pole. A compass can help to determin which way to wire it. From the picture it looks like some of the coil is dark, rather than bright copper color, so it might be burned and shorted.

[kcav8or]

That dark wire in the coil isn't burnt, but it appears to be colored completely black on purpose. Maybe they ran out of one color and used another? Odd.

I found this on Wikipedia, and it looks like the proper coil configuration. (I know it says generator, but they are basically equivalent in the way they are wired.) Do you all agree?

http://en.wikipedia.org/wiki/File:Co..._generator.jpg

[Tom Wesenberg]

Yes

[kcav8or]

Can anyone tell me the number of turns on the stator coils for a 6-volt motor? I plan, of course, to count them as I unwind the existing ones, but I'm interested to see if there is a difference between a true 6-volt horn and my hobbled 12-volt unit, with one neutralized coil.

[kcav8or]

On the diaphragm, there is a gasket on each side that looks like it is made of wax paper. I'll have remove those to repaint the diaphragm. Do you think I can just cut new ones out of wax paper with an x-act-o knife?

[kcav8or]

Good news! I was starting to unwind the coils and discovered that one of the power wires was broken inside the insulation. When I hooked it up to the battery charger, the motor spun. I went ahead and put it together enough to get an "oo-gah" out of it. There's still quite a bit to do to it, and I might still rewind the field coils since I have new wire, but it was nice to hear it!

[Mike V. Florida]

Originally Posted by kcav8or

Good news! I was starting to unwind the coils and discovered that one of the power wires was broken inside the insulation. When I hooked it up to the battery charger, the motor spun. I went ahead and put it together enough to get an "oo-gah" out of it. There's still quite a bit to do to it, and I might still rewind the field coils since I have new wire, but it was nice to hear it!

There is a member that has on the bottom of his posts;

Fix it until it's broke.

I would leave the coils alone unless there is a real problem them. Many "what now" statements started with "I'll just replace it with new".

[kcav8or]

This weekend I polished the chrome on the horn, and thought I'd share what I learned. Before polishing, it was dull and had a lot of surface rust. The first picture shows the parts after polishing with a commercial chrome polish. It looked pretty good, but still had quite a bit of surface rust. The second picture shows what it looked like after cleaning with aluminum foil and cheap soda. Nearly all of the surface rust is now gone.

[Tom Wesenberg]

Thanks for the tip. I have surface rust on my original nickel headlights and radiator shell and wonder if this would help on nickel?

[kcav8or]

I think it would, but test it somewhere inconspicuous first. The reason this works so well is because of the carbonic acid in the soda, combined with the fact that aluminum foil is softer than chrome, but hard enough to abrade the rust. It still needs to be sealed with something to seal the pinholes that caused the rust in the first place. I just used paste wax, but there might be other things that work better.

I will be doing the same thing to the radiator grille frame and the instrument panel. They have less severe rust than the horn, so they should look great after this.

[barnstuf]

I recall the Hutchins horn and they were made in the mid west for quite a few years, Missouri as I recall. They were originally marketed for use on boats but when folks began restoring Model A's a new market for them emerged. They were sold as either 6 volt or 12 volt but as I recall they could be changed quickly from one to the other by simply removing the cover and relocating one wire. When the business owner retired the business was not sold but simply closed. They were a dependable horn and were chrome plated. Sold for about $39.95 and sounded close to the real Model A horn sounded.

[kcav8or]

That's good information. Any ideas when they were made? This one isn't original equipment, but has been on the car for a long time.