Model A Voltage Reducer Just for Model A's?

[leo]

Will the 12 to 6 volt reducer which allows you to use a Model A Ford ahooga horn in a vehicle with a 12 volt system work with any 6 volt ahooga horn? I know it sounds rather obvious but then again I'm electrically challenged....

[Tom Wesenberg]

If the horn draws about the same 5 amps as an original horn, then I see no reason for it to not work. Just wire it in series with the power wire.

[eagle]

There a basically two types of voltage reducers commonly used. The resistor type which limits the current, and into a given load, thereby the voltage. That's what you have and so you will need to verify the load is similar. As Tom says, if it is about 5 amps, it will work. The second type is a voltage regulator, which puts out a constant voltage not dependent on the load. This type is what you would use for a varying load such as electronic equipment or such. Of course in reality this type is also current limited, it will smoke and quit working if you try to overload it beyond what it is spec'd for.

[leo]

Hi guys, how do you determine how many amps a horn will draw? I don't recall seeing that posted on any old horn identification tag.

[BILL WILLIAMSON]

I read of a Guy that hid a coil inside his frame rail & used it for a voltage drop, for his HORN.
Bill W.

[Synchro909]

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Originally Posted by BILL WILLIAMSON

I read of a Guy that hid a coil inside his frame rail & used it for a voltage drop, for his HORN.
Bill W.

I did that. Might even be the guy you read about. Should I be worried??

[Tom Wesenberg]

Originally Posted by leo

Hi guys, how do you determine how many amps a horn will draw? I don't recall seeing that posted on any old horn identification tag.

Just unhook any wire in the horn circuit and connect an ammeter between the two terminals just disconnected. Or, if you original ammeter is accurate, just blow the horn and read the meter. I find when the adjustment screw gives the right sound to the horn, it's drawing about 5 amps.

Disconnecting the horn/lights wire at the cutout is a good easy place to install an ammeter for the check.

[leo]

Thank you Tom.

[BILL WILLIAMSON]

Folks with a Multi-Meter: Read your little book, play around with it, there's lots of uses for it !--It's NOT MYSTERIOUS. AND, don't forget to "play" around with your TRUSTY old test light!
YEARS ago, Chief rigged one, using an old ICE PICK & a tail light bulb.
"Maybe" I can find out why my HAIR DRYER suddenly DIED??
Fuzzy Bill W.

[leo]

Hey Bill, hair dryers pull a lot of juice, don't zap yourself, when those things croak just fling them and replace. Be safe and Merry Christmas.

[Tom Wesenberg]

If someone needs a multimeter, here is my favorite, and it cam measure up to 20 amps DC, which is ideal for checking lights, coil, and the horn amps on the Model A.
Buy it now with shipping is only $17.

http://www.ebay.com/itm/322361765955...%3AMEBIDX%3AIT

[leo]

Hey Tom, got one of these. Set the dial to what for the amperage test? Merry Christmas.

[Tom Wesenberg]

Originally Posted by leo

Hey Tom, got one of these. Set the dial to what for the amperage test? Merry Christmas.

Just move the red lead up to the 20 socket, and turn the knob to 20 A in about the 3:30 position. The black lead goes to the more negative terminal, so if you are checking the generator output, the generator cutout gets the black lead and the terminal box wire removed from the cutout gets the red lead.

If you are checking the horn draw then the more negative would be the negative battery post, so that gets the black lead, and the red lead goes to the horn, while another wire already is feeding power to the horn from the battery + post.

[sphanna]

Hey Leo: Always listen to Tom cause He is a great resource as well as several others on this site. But I just used a 6 volt coil that I had extra and installed in series to an extra horn that I had. Now I have a second horn under the hood that sounds just like the original horn that I run with a variable resistor from an old heater motor rheostat. Both work perfectly with my 12 volt system and I have a spare horn all set up. I put an old push button switch under my dash rail to operate it.
I see that Synchro909 also did this.

[leo]

sphanna, you are light years ahead of my abilities. Merry Christmas.

[leo]

Happy New Year. Hey Tom, can this test be done with a small sealed 6 volt lead acid battery that only puts out about 4.85 amps?

[briphaeton]

What I use is a Ohmite RESISTOR, 2 OHM, 100 WATT, ADJ TUBULAR, WIREWOUND, +-10% TOLERANCE.The Galco part number is D100K2ro.
It is a adjustable resister so you get adjust what sound you want from your horn. I found it in a old Restorer article? You have to make a simple bracket that mount on the inside frame rail so it's out of sight. Works great.
Brian

[leo]

Sounds wild bripheaton, and it just sits there exposed to the elements with no chance of shorting out if it gets wet?

[briphaeton]

Hi Leo
It's a tubular resistor and has a threaded rod through it with delron insulators on each end. The bracket that hold the threading rod gets it off the frame. It's protected by being inside the frame rails (even more if you use engine splash pans) and only has power when it's grounded it by blowing the horn. I've used it for years without any trouble with rain. I wish I could find the article for reference. The best thing you have a perfect sounding horn with 12 volts.

[bettlesr]

I never liked the sound I got with the dropping resistor,, so I rewound the coils with more turns of thinner wire.