Identify Horn Motors Brands

[mrtexas]

I thought someone might find this interesting. I pulled out the dozen or so core horns I bought a couple years ago. I have 5 Stewart Warners, 3 Spartons, one GMI, one Ames, one 32 and 2 EA labs. I couldn't seem to find all this information in one place on the web so here it is. Some of the information came from "How to Restore Your Model A" volume 1 and "Technically Speaking" volume 3.

Identify Model A Ford Horn Motors
There were 5 kinds of Model A Horns for 1928-1931. Most of the time they can be identified by the brand stamped into the motor base, horn cover, or horn bell. My several horns had mixed up or wrong covers and horn bells as well. They can also be identified by the motor frame width and the armature shaft diameter. These are only the most common types. Several of the brands have some variations I don't show.

GMI
1" frame and 5/16" shaft.
The brush holder is unlike any other brand


Stewart Warner
11/8" frame and 1/4" shaft
Caution: the nut on the end of the armature is a left handed thread


Sparton
3/4" frame and 1/4" shaft


EA
3/4" frame and 1/4" shaft


Ames
11/8" frame and 5/16" shaft


32 Ford
Bullet shaped cover


32 Ford
Note the different hole pattern in the 32 on the left. The 32 Horn sits on a bracket on the fender unlike the Model A which hangs from the headlight bar. If a 32 horn is installed on a Model A, the drain hole for the motor will be on the top rather than the bottom.


http://members.fortunecity.com/pjsauber/Akebia.htm

Some more differences:

Horn bases
From left to right, EA, Sparton, Ames, Stewart Warner and GMI. The GMI is the only one with an oilite bearing on the bottom:



Sounding springs
The one on the left is for Sparton and the other is for Stewart Warner:

Terminal blocks
The one on the left is for EA and the other is Sparton. Sparton goes into the insulator with legs and the EA with a single fold.

[HoarseWhisperer]

I have the GMI with the vertically opposed brush holders.
Great sounding horn that doesn't seem to require much maintenance.

I know of another FB'r that has one.

We swapped covers to have the proper size GMI logo for the respective year of our vehicles.

[Steve Plucker]

Ever think about submitting this to Model A News or The Restorer for an indepth article on these differences?

Both clubs are chomping at the bit for such articles.

Pluck

[BudP]

Agree with Pluck!

[BudP]

Addendum: I agree with Pluck because I am a beginner in this hobby. As a beginner, I broke off the nut on the first Stewart Warner horn I tried to rebuild (I missed the line in Les Andrews book that S. W. has a left-handed thread). Since this thread is about Model A horns, does anyone have any suggestions on how to join that broken post? Soldering it did not work.

[Special Coupe Frank]

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Thanks for this post Mr Texas !!!!

I now know that I have a Sparton horn on my '28 !

( No tags or external markings )

[eswanson]

good post, I have a Stewart Warner horn and then a FM stamped back. I like the details and all is helpful.

[sonny30coupe]

Nice info.

[Tudortomnz]

This is very interesting & you should do an article as suggested. The EA Laboratories [FM] pictured must be the earlier type . Later EA motors look same as Sparton & have a flatter cover end. Your pictured one has a different piece at the adjuster screw to attach the cover end which protrudes more on earlier EA's.
Trying to send a photo of mine will only mess up my pc.

[Ron in Quincy]

The very early Model FM (hump back) cover is not interchangable with any other horn cover due to the mounting screw and adjuster location; the two wires plug in from the bottom and not from the side.

The very early Ames cover only has two vertical ribs and is not interchangable with any other horn cover due to the location of the mounting screw and adjuster location; the cover does not have the " Diamond" on the back of the cover like the 2nd generation; the wires also plug in from the bottom and not from the side.

Ron

[mrtexas]

I broke down my 12 horns today for painting the bases. I had to be careful not to twist off the left handed Stewart Warner armature nuts as some of the armatures were not the same as the base brand.

Some more differences:

Horn bases
From left to right, EA, Sparton, Ames, Stewart Warner and GMI. The GMI is the only one with an oilite bearing on the bottom:



Sounding springs
The one on the left is for Sparton and the other is for Stewart Warner:

Terminal blocks
The one on the left is for EA and the other is Sparton. Sparton goes into the insulator with legs and the EA with a single fold.

[Steve Wastler]

I agree with the others, put this all together and do the in depth article. Great info, thanks for sharing......

[bogiediver]

Sorry to bring up an old thread...

I found the pictures and info to be very valuable.

I would like to request any info on cleaning / rebuilding that might be specific to each version that would be in addition to, or in replace of, the general cleaning / rebuilding 'how to' in the Les Andrews book.

My horn is a bit 'sluggish' - plans are to check all electrical wiring and grounds, but will probably take the horn apart to clean since I have no idea when (if?) it was done last.

NOTE: BudP's question above wasn't answered about fixing a busted left hand stud..

Also, I read in another thread about using a relay for the horn - be interested in specifics of how that would be done...

Thanks for sharing this...

[mrtexas]

Originally Posted by BudP

Addendum: I agree with Pluck because I am a beginner in this hobby. As a beginner, I broke off the nut on the first Stewart Warner horn I tried to rebuild (I missed the line in Les Andrews book that S. W. has a left-handed thread). Since this thread is about Model A horns, does anyone have any suggestions on how to join that broken post? Soldering it did not work.

If it were me, I would cut off the left hand threads, then drill and tap a right handed fine theaded screw into the end of the armature. Right hand thread is OK since the other 4 brands use right handed nuts.

[mrtexas]

Originally Posted by bogiediver

Sorry to bring up an old thread...

I found the pictures and info to be very valuable.

I would like to request any info on cleaning / rebuilding that might be specific to each version that would be in addition to, or in replace of, the general cleaning / rebuilding 'how to' in the Les Andrews book.

My horn is a bit 'sluggish' - plans are to check all electrical wiring and grounds, but will probably take the horn apart to clean since I have no idea when (if?) it was done last.

NOTE: BudP's question above wasn't answered about fixing a busted left hand stud..

Also, I read in another thread about using a relay for the horn - be interested in specifics of how that would be done...

Thanks for sharing this...

The usual suppliers have a small horn relay for Model A horns. They are small enough to fit inside the cover. The advantage is that the horn button amperage would be much reduced.

There is really nothing specific to a brand of horn. The only real differences are in armature bearing diameter, motor frame width, and style of brushes. All are DC motors turning the same sort of end that makes the sound.

[HoarseWhisperer]

Originally Posted by mrtexas

Horn bases
From left to right, EA, Sparton, Ames, Stewart Warner and GMI. The GMI is the only one with an oilite bearing on the bottom:

By any chance would you happen to have a close-up pic of GMI oilite bearing?

Thanks.