Original sparton horn

Vanspeed

Well-known member
My horn recently is on the fritz. I have the cover off and oiled the bushings. If I rotate the motor by hand a little and hit the button it works. If I don’t slightly rotate it by hand though it does nothing. It spins just fine when it does spin. Could this be brushes going bad? Connections all look fine.
 
sometimes just cleaning up the armature will get it going again. you could rub it with a bit of fine sandpaper to shine it up. clean the brushes but be gentle. may help.
i don't know how advisable this is but i have washed mine with a quick squirt of vd-40. she fired rite up again.
those horns are pretty bullet proof.
 
I cleaned the armature and the brushes. I used a very fine scotch brite pad and it shined up real nice. Back in the car, same results. If I spin it to where it is free between the teeth on the ratchet it fires up and sounds great. But the moment I try to hit it again it doesn’t move, makes a fine click sound. If I rotate it again by hand it works and sounds great. I am stumped.
 
I left out a little info. I converted this car to 12v a few years back and used one of those in line reducers that tuck up inside the cover. I removed that and hooked it up to straight 12v. With just quick little blasts it works just fine. Obviously that inline reducer is causing the problem. This car is original paint with patina and I do not want a new 12v horn as it will just look out of place. Is there somebody who rewinds these to work on 12v? Are there other options to get this working correctly?
 
There are different resistors available. Some work better than others. Try a different resistor. I had a resistor in my horn that would get too hot and not pass enough current.
 
the reducer is not matched to the amps the horn needs—- measure the voltage the horn is actually getting during operation.
Perhaps a second of those reducers in parallel.
Or you could do a 12v conversion like I do with a sawsall.
 

Attachments

  • IMG_3113.jpeg
    IMG_3113.jpeg
    202.8 KB · Views: 36
There are different resistors available. Some work better than others. Try a different resistor. I had a resistor in my horn that would get too hot and not pass enough current.

It did get pretty hot when just quickly hitting the horn button.
 
Whenever my horn starts acting up, which is not seldon, I clean the clapper and very lightly grease it. An "old dude" told me to do that. Now I'm the old dude.
 
I read that to convert them to 12v you use 24g coated rf wire. Original horn fields were 20g, wrapped 45 turns. When using the 24g you wrap them 100 turns and this will allow it to be used on 12v systems. Anybody try this method?
 
There is a gentleman by the name of Steve Smith who can rewind that horn for you. I don’t have his contact info at the moment but he advertises in the MAFCA magazine as well as other places. He has done 3 horns for me and they all work great. His price is quite reasonable.
 
I read that to convert them to 12v you use 24g coated rf wire. Original horn fields were 20g, wrapped 45 turns. When using the 24g you wrap them 100 turns and this will allow it to be used on 12v systems. Anybody try this method?

If I remember correctly the two fields are wound in opposite directions. Check before removing the original wire.
 
There is a gentleman by the name of Steve Smith who can rewind that horn for you. I don’t have his contact info at the moment but he advertises in the MAFCA magazine as well as other places. He has done 3 horns for me and they all work great. His price is quite reasonable.

I found his email in another thread, thanks. I sent him a message as my car also has an EA laboratories wiper motor that has been disconnected since switching to 12v. Looks like he does them too. I will let you know what he tells me.
 
IMO, you should forget using a resistor to drop 12 volts to 6 through the horn. I gave up on that years ago and rewound the field coild with thinner wire. I have done that on all 4 of my cars and all 4 horns work just like an original on 6 volts. I think a resistor is the easy way out and we all know how that usually works out - it doesn't.
FWIW, I reconfigure the field windings in the starter and in the horn when I convert to 12 volts and they both work well and no one has ever noticed.
 
The ONLY horn voltage dropping resistor that has ever worked for me is the one Bratton's carried. Of course Bratton's in gone now and I don't remember the brand (if I ever knew). Been working fine for ~9 years now.

Like others have said, better to rewind.
 
Just talked with Steve and he is going to convert the horn over to 12v. I know an original sparton horn is a nice thing to have and not modify but a new 12v horn will not look right on a car with its original paint that has seen 96 years of abuse. Thank you all for your help. Another reason why this forum is so great!
 
The original 6-volt horn:
(1)The field coils are wound in opposite directions.
(2)The field coil wire is 20 gauge coated wire.
(3)There are 45 turns, 6 -7 turns per layer, not
perfect is OK.
(4) After completion it was sprayed with varnish to
insulate.
Rewind for 12-volts:
(1) Same as above.
(2) Use 24 gauge coated wire.
(3) 100 turns, 6-7 turns per layer, not perfect is OK.
(4) Same as above.
 
The original 6-volt horn:
(1)The field coils are wound in opposite directions.
(2)The field coil wire is 20 gauge coated wire.
(3)There are 45 turns, 6 -7 turns per layer, not
perfect is OK.
(4) After completion it was sprayed with varnish to
insulate.
Rewind for 12-volts:
(1) Same as above.
(2) Use 24 gauge coated wire.
(3) 100 turns, 6-7 turns per layer, not perfect is OK.
(4) Same as above.

If the rewound horn still sounds like someone choking a chicken, remove a couple of turns from the field windings. If it is a 6 volt horn, one turn is usually enough.
 
I just went through 3 horns, cleaned & adjusted them. Two worked fine but the third was running very slow. Just out of curiosity switched it up to 12 volts & it worked perfectly even tho it was still wound for 6 volts. I know it needs further rehab but just going to leave it for now & maybe put it on a 12 volt system.
 
Back
Top