55 Horn tones

[CadDad]

 
    My 55's passenger side horn is shot and I am looking for a replacement. Driver's side works fine. I have been looking in some parts catalogs and need to know what tone it is. Is it the high or low tone? Since it never worked I couldn't compare it with the one that does. Thanks for the info.  Paul

[Walter Youshock]

There are rebuild kits available.  I've seeen them on ebay.

Try this:  Remove the tone adjusting screw on the top of the horn and liberally spray WD-40 or PB Blaster in it and let it soak overnight.  Reinstall the screw and test the horn.  You can use a battery charger--the horn bracket is ground and the wire plug is the positive.  At least you might be able to bring it back to life.

[CadDad]

 Thanks Walter. I'll spray it in the morning let it see awhile and see what happens. 

[CadDad]

 Well nothing. I'm not getting any current between the two points. All contacts are good. Nothing looks out of the ordinary.

[Walter Youshock]

Did you reinstall the tone adjustment screw and tighten it to where you feel a little resistance?  That should be close to the original adjustment.

It might take more than one application, too. 

[CadDad]

The screw and flapper is all good. It was never frozen. The problem I am having is that there is a loss of power between the two contacts. Without grinding off the rivits and looking behind the magnets and windings I really can't tell where the problem is.

[Mike Josephic CLC #3877]

Paul:

In addition to the penetrating oil treatment, try the following:

-- Lightly tap the horn body with a rubbber mallet.  Sometimes, a few dirt particles can
get stuck in the internal contacts
-- Turn the adjustment screw all the way in -- then back it off to standard setting
sometimes this can help as it increased the available current to the horn coil and can
help "unstick" things.  Try adjusting it with 12V power on and see if you can get any
sound.

If none of these things work, then time to look for a new horn.

I personally would not bother to rebuild it.  You have to grind off the rivets (as
you noted) and it's a nasty job.  Plus, you will never get it to look "correct" as the rivets
need a special tool to apply.  You can likely find a new set on E-Bay for not much $$$.
That's what I did for several cars.

Mike

[The Tassie Devil(le)]

I found that when I had a couple of horns that weren't working, the problem was that heat inside the Horn has melted the Plastic sleeve that the coil windings is around and stopped the Plunger from moving freely.

The way these horns work is that the diaphragm plunger is moved by a magnetic force one way to strike a spring-loaded current breaker (Switch) and this releases the plunger and causes the diaphragm to move back, making the horn noise.  Constant back and forth creates the noise that makes the horn sound like it does.

To disassemble the horn I drilled out the rivets and separated the parts, taking care not to tear the paper insulating pieces that surround the diapgragm, and with a sharp blade, trimmed off the offending plastic so that the plunger could move all the way to the back.

Assembling was a matter of either replacing the rivets with other rivets, but I used metal threads, so that I could pull it to pieces if it happened again.

Bruce.

[CadDad]

 I sure appreciate all the input guys! Thanks,  Paul

[Mike Josephic CLC #3877]

Let us know if you get them to work!

Mike

[Walter Youshock]

...and don't be afraid to look outside Cadillac suppliers for the parts!  These were used across the board from Delco!

(HINT!-HINT!)

[CadDad]

 I drilled out the rivits and popped apart the horn and still saw nothing wrong. I started looking for suppliers on line.I have been looking at Delco horns off (GULP) Chevrolets. Seems like there are a lot more 50's Chevy horns than Caddy horns. Is there much difference in the tones? Am I comitting some sort of cardinal sin doing this? I found out it is the low tone horn I need. If any of you guys have any thoughts or have a low tone to sell, I am all ears. This horn and a heater control valve that I sent out finishes about all of my Caddy jobs (untill something breaks or I get bored)

[Mike Josephic CLC #3877]

A low tone Chevy clamshell type would work and look close to the caddy.  If I
remember correctly the difference is in the connector (spade type vs. plug in type).
There are also some that have a red insulator surrounding the connector and some
do not.  Caddy and Chevy horns can be interchanged and will work.

Bottom line -- it would sound OK -- just depends how picky you want to be on
authenticity.

If you can get a copy of Hemmings -- there are lots of '55 Caddy horns out there.
Also try E-Bay -- they are on there every week.

Mike

[The Tassie Devil(le)]

When viewing the internal hole where the plunger fits, is there any plastic at the bottom of the hole?

Bruce.

[J. Gomez]

Paul,

help sites;

http://www.clubfte.com/users/dmptrkr/hornrepair.html
http://temp.corvetteforum.net/classics/l78vetteman//1-15-07/mid_year_horn_rebuild.pdf

and in case you give up a rebuilder;

http://www.classiccarhorns.com/