Aooo (OK)......ga (weak)!!!!

[31 Model A]

Seems my horn is getting a bit weak with the AOOOGA!!! I press the horn and I get the AOOOOO and then barely the..... GA!!!! Bad wire connection?

[Redbird]

There is an adjustment screw on the back side of the horn. Try turning a little each way.

[31 Model A]

Originally Posted by Redbird

There is an adjustment screw on the back side of the horn. Try turning a little each way.

Thanks....I'll give it a try tomorrow, she's bedded down for the day.

[Tom Wesenberg]

Remove the cover and hold some fine sandpaper against the armature as it spins. I did that to my friend's car and after about 10 seconds it started speeding up. It was sounding like new after about 20 seconds of light sanding on the commutator.

Also put a couple drops of oil on the two felts for the armature. Make the final adjustment after the cover is screwed back on.

[31 Model A]

Originally Posted by Tom Wesenberg

Remove the cover and hold some fine sandpaper against the armature as it spins. I did that to my friend's car and after about 10 seconds it started speeding up. It was sounding like new after about 20 seconds of light sanding on the commutator.

Also put a couple drops of oil on the two felts for the armature. Make the final adjustment after the cover is screwed back on.

Will do, thanks..............

[30ccpickup]

Sponsored Links (Register now to hide all advertisements)

Follow this and it should give you the ga.
http://modelabasics.com/horn.htm

[31 Model A]

Originally Posted by 30ccpickup

Follow this and it should give you the ga.
http://modelabasics.com/horn.htm

Can't go wrong with that, especially having pictures helps this old man.

Thanks...........

[Mike V. Florida]

The ratchet, rubs on the that wedged shaped part on the diagram. As the motor spins up to speed the slower speed gives to the AH sound. Once it hits the right speed yo get the OOOO sound and as the motor spins down you get the GA.

If you have a weak motor you will not get the correct sound.
If you have a misaligned ratchet you will also not get the correct sound.

[Mitch//pa]

oiling the felts will fix you up... i use ATF
post 4 is pretty complete

[31 Model A]

Well gentlemen..........I removed the cover, oiled the felts, upper and lower, took some fine 220grit sandpaper and cleaned the commutator. I get a strong AOOOOOO...but no GAAAAAA. If I adjust the clicks to the right, it tightens up and the armature doesn't move, back it off it's fine but still no GAAAAA.

[Mike V. Florida]

Grease the ratchet. The motor is stopping too soon.

[31 Model A]

Originally Posted by Mike V. Florida

Grease the ratchet. The motor is stopping too soon.

That I did not do. Thanks

[Marco Tahtaras]

Originally Posted by Tom Wesenberg

Remove the cover and hold some fine sandpaper against the armature as it spins. I did that to my friend's car and after about 10 seconds it started speeding up. It was sounding like new after about 20 seconds of light sanding on the commutator.

Also put a couple drops of oil on the two felts for the armature. Make the final adjustment after the cover is screwed back on.

I can add a little to that. I've done the same periodically for decades. I back the adjuster off 4-5 clicks so the ratchet does not contact the diaphragm and the motor can spin freely. Then I use 400 grit or finer (usually 500 grit on hand) so it's more like cleaning and polishing. I don't want to introduce grooves to the commutator as courser paper will do. I can barely reach the horn button with my right hand to hold it down while holding the thin strip of paper against the commutator with my left index finger. It seems I'm always by myself when I need to do this!

Now here is another "twist" to the story. Some years back I was giving it some thought. It seemed my horn just hadn't been used enough to warrant much in the way of servicing but did indeed act severely bogged down. I went out to the care and backed off the adjuster counting five clicks for reference. I pressed the horn button and the motor began spinning albeit sluggishly. After a few seconds it picked up a notch clearly evident from the pitch of the motor spinning much like it does when using the sandpaper. After a few more seconds it picked up another step. With a couple more episodes of this it finally seemed to find it's peak.

I tightened the adjuster the same five clicks (to my original setting) and it worked like a charm. I took it one click tighter and still worked flawlessly. One more click was too much (which was fine) so I backed it to my original setting and never had to touch the horn again until the car once again sat for a period of time.

I've been doing the same ever since.

[Tom Wesenberg]

My 1929 horn button wasn't making a very good ground because it had gone so long unused. I pressed the button rather firmly and rolled my finger around on it so I could somewhat scrub the grounding surface. This got it working like it should.

[31 Model A]

Took the cover back off and greased the ratchet and below rod. Still no improvement. Hold the horn button down and all I get is the AOOOOO, no release for the GA.

[MikeK]

There is a tension spring that keeps the motor shaft axial play biased rearward, separating the ratchet and diaphragm pawl. THREE things must be correct to get the correct ...gaa at the wind-down: 1) The backward shaft end play controlled by the 'adjust' screw. 2) Maximum forward end play, fixed by spacer washers as needed on the front end of the motor shaft. 3) Tension of the spring shown below.

The motor armature is/should be offset from the magnetic center of the field coils toward the rear, away from the diaphragm. When the motor is powered the armature moves forward magnetically, overcoming the force of the spring shown.

I suggest you look at both the armature forward end play, which needs to be present to the correct amount, and the tension spring, which must also be set correctly. I assume you have the diaphragm oriented correctly, following the tiny position locator hole and frame detent.

[31 Model A]

No dice fellas, I keep rolling craps!!!!

[ian Simpson]

Originally Posted by Tom Wesenberg

Remove the cover and hold some fine sandpaper against the armature as it spins. I did that to my friend's car and after about 10 seconds it started speeding up. It was sounding like new after about 20 seconds of light sanding on the commutator.

Also put a couple drops of oil on the two felts for the armature. Make the final adjustment after the cover is screwed back on.

CAUTION: Do as Tom and Marco say and use SANDPAPER. Emery paper and some of the modern sandpaper replacements will contaminate the commutator with abrasive and destroy both brushes and commutator.

Ian

[MikeK]

Originally Posted by 1930 coupe

What is the correct forward end play? Is it when the armature is centered in the fields?

The visual center and the magnetic center are not necessarily exactly the same. If a motor is running with no shaft end play limits or forces the armature will find that exact center. Repair/rewinding any part will slightly move that point. The horn must have the forward end play set so this magnetic center point is NEVER reached. The armature must be rearward so any application of power will tend to drive it forward.

The forward end play limit is set by the contact of the diaphragm pawl to the ratchet wheel. During manufacture, with all identical parts moving down the line this point was fixed by the height of the U shaped field frame. Now, with tolerances out the window with replacement and swapped parts, some people adjust by peening around the diaphragm pawl to move it in/out, by changing diaphragm shim thicknesses, or by stoning the ratchet and pawl to modify the engagement.

The spring in my post above is another point of question. Most of the replacements I've seen are way to thick/stiff compared to originals. The rear 'adjust' screw only finds the horn work point. That not-too-easily accessed and almost never adjusted front spring has a major influence on the overall voice.

[31 Model A]

Neil Stegall, the Horn Man contacted me and said, send me photos.........I did.

I have a Steward Warner and Neil said it looked OK to him and for me to blow it out, especially around the armature real good with an air hose, I did, and...it's back to where it was. Oiling the pads and greasing the ratchet and spindle was good to do also since I'm sure it had not been serviced like many other areas had not for some time.

Thanks Neil and all here for your assistance.