Model A Horn Not Working

[KeansClassics]

The horn on my 1930 Ford Model A is not working. I was wondering if someone could tell me if and how to bench test it. If I know its working off the car, then that will tell me that it has to be something else down the line. I have taken the horn off the car and taken it apart to clean it up. I might put a slick of paint on it to make it look better, but I need to know that it is working before I do that.



Thanks for the Help!

[Clem Clement]

Clean the commutator with a emery cloth. Check the brushes ansd brushholders. Oil the bearings and check the wire ends. Backoff the adj screw so the armature end doesn't hit the vibration plate. Power up the horn and see if the motor runs. If it is dead, do a contuniuity check on the armatrue segments. Let us know what you find out.
Clem

[Jon-Ohio]

I have a 10 amp battery charger (on the 6 volt setting) that I use to bench test motor horns including 'A' horns. Make sure the armature commutator bars are oil free and clean and that the adjusting screw isn't too tight against the diaphram. Also lightly oil the armature felts in the base and frame - armature should turn easily by hand.

[Tom Wesenberg]

In addition to what's already been posted, when you apply 6 volts to the 2 terminals, it doesn't matter which one is positive. The horn body DOES NOT need to be grounded, as it plays NO part in the electrical circuit to run the horn motor.

[KeansClassics]

I placed the two wires on the battery last night and the horns Motor did turn over. Is it suppose to make a noise from that spinning?

[Tom Wesenberg]

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Yes, just turn the adjustment screw in until the armature is moved forward enough for the wavy washer to touch the chisel point of the diaphram.

[KeansClassics]

I was able get the horn to work on the bench so I put it back on the car. I then pushed the horn button on the column and it did make noise for a second but then nothing. Does anyone know where to go next to make this thing work? The wires are connected good from the horn to the wire in the column and the wire to the starter. The horn button was getting warm after pressing on it for awhile if that explains anything.
Thanks!

[Steam Engine Pete]

Andrew,
You have excessive resistance in the ground circuit causing voltage drop. The warm horn button is an indicator of a poor connection. The horn circuit is not getting proper ground from the button.

Pete

[Tom Wesenberg]

Pete explained why it's getting warm. I see this happen more on repro horn buttons. In fact I don't recall having felt a warm original. I'd try pressing the button and moving it around while it's pressed to see if you can't get a better contact. That offen works on more cars than just the Model A.

[Evan Lewis]

Andrew,
Sometimes on my '31 Tudor the horn will not work from pushing the horn button. I can usually fix the problem by removing the light switch body from the bottom of the steering column and use a Q-tip soaked in solvent to remove oil that has settled on the metal center of the bakelite swich contact. This removes the oil from the steering housing that prevents keeps the horn rod from grounding. This usually works for me; hope it does for you.
Good luck!
Evan Lewis

[Fred K-OR]

Originally Posted by KeansClassics

I was able get the horn to work on the bench so I put it back on the car. I then pushed the horn button on the column and it did make noise for a second but then nothing. Does anyone know where to go next to make this thing work? The wires are connected good from the horn to the wire in the column and the wire to the starter. The horn button was getting warm after pressing on it for awhile if that explains anything.
Thanks!

I have the exact same situation. The horn works great on the bench but will only work sort of, when I am running fairly fast with the engine.

I will have to check out some of the suggestions above.

Thanks.