1933 Buick Klaxon 26-E Horn Capacitor

[1933gray]

Hello, I have two horns on my 1933 Buick, one of which does not work. When power is delivered to the horn, it makes a simple "click" noise, but nothing more. After speaking to someone who has restored many Buicks, they suggested that it is typically the capacitor (or condenser) that goes out. I sanded the contacts and after surfing the web, I found that the replacement capacitor I should use should be between 0.47-0.68 uf at 250V. Does anyone know the actual rating I should use for this model horn? Or am I even barking up the right tree? Is there something else wrong with the horn?

 

Thank you!

[TerryB]

Pulling up some electronics theory I would expect the capacitor or condenser is there to buffer the horn’s contact points from arcing when they open and close under normal use, just like a condenser does in a points type automobile ignition.  If you buy a new condenser you could disconnect the one in place and use clips to jumper in the new one and see what happens.  It’s possible there is something wrong with the windings of the coil that activates the points too.  You have to pick one thing at a time and see what happens.

[Oldtech]

Capacitors in this application aren't fussy. Anything in the range is fine. 

[TerryB]

In giving it more thought, the capacitor and the DC coil that makes the points open and close could be part of a L C tuned circuit to operate the horn. That seems like an overly complex circuit for an automobile horn but you never know.  In the tuned LC circuit, the capacitor value get a little more specific in value.

[32buick67]

I have found this site to be very helpful for my 1932 Buick Klaxon Model 26 high-low note setup, maybe it can be of some help for you too.

http://www.delcoremyhistory.com/Service Manuals/klaxon horn 1933.htm

 

The capacitor/condensers on my horns were fine, seemingly robust after 90+yrs, based on stats, its unlikely the caps/condensers had much wear...how many times was a horn button pressed per year...

My challenge was to adjust the air gaps to ensure proper tones and not to get the binary hard off-on click you mention when 6V was applied via the steering wheel horn button.

I measured amps to each horn, but the results were more of a guide vs documented specs, especially considering that the battery voltage might vary slightly from car to car.

My final solution to achieve a nice dual note sound was to adjust the air gaps in each horn to my liking.

Keep in mind that temperature fluctuations might impact your settings.

Hope you can avoid RLC engineering techno babble regressions for this, hope its just a simple turn-of-the-wrench air gap issue....but if it turns into RLC mayhem, folks on this forum can help...