Testing horn with multimeter

[Merc_Girl]

Hi folks
Looked at a few threads but can’t find anything suits my query.

So, I have the horns removed from Bessie and want to check if the horns themselves have a problem.

I have a handy multimeter but no idea what bits to test and how 🙃

Is there an idiots quide anywhere would one know?

Many thanks

[rwmastel]

(Disclaimer: Electronics are a weak spot for me.)

I would think you would just provide a ground and then touch the other connector with 12v and Beep!!  Are you using the multimeter because you think you'll find too much resistance within the horn?

[Merc_Girl]

Using multimeter to check if circuit within horn working?

[DavidAPease]

Hi, Katie,

I doubt there's anything useful you can do with a multimeter to test the horn (at least without dismantling it). 

I agree with Rodd: Connect the ground side of the horn to the negative terminal of your battery (any 12 volt car battery), then use another wire to briefly connect the positive terminal of the battery to the other side of the horn connections.  It should beep (or honk...). 

If it doesn't, then it might be time to look inside, where the multimeter might be useful.

           -David

[Merc_Girl]

I’ve sort of already dismantled the horn, my curiosity got the better of me as I was intrigued as to why it weighed so much 🤓

[BobH]

The electro magnet is the only electrical part in there, it probably accounts for most of the weight

You can measure the resistance of the coil, if you select the 200ohm scale on the meter you should measure probably less than 10 ohms across the coil

[Cees Klumper]

Some horns have a small adjustment screw that regulates the 'resonation' of the membrane to produce sound, and slight adjustment of this screw can bring an old horn, that perhaps only produces a 'click' on activation, back to loud life.

[Merc_Girl]

Thanks chaps for useful info! Will start ‘playing’ at the weekend 😁

The disc thingy (membrane ?) didn’t appear to be screwed in on one horn , which I presume it should be given there is a screw thread on the end of the post it sits in?

[66andBlue]

Hello Katie,
in Pagodaworld 21 (2017) I described the testing and tuning process that might be helpful to you. Do you have access to the article?

[rwmastel]

Mdsalemi restored a pair of horns.  Did you search the forums for others who may have?  They could be a wealth of info.

[mdsalemi]

Hello Katie,
in Pagodaworld 21 (2017) I described the testing and tuning process that might be helpful to you. Do you have access to the article?

PW#21 will be available to those that don't have it, in Pagoda World Book, Volume III (issues 21-30) which we will make available sometime later this year.

[mdsalemi]

Mdsalemi restored a pair of horns.  Did you search the forums for others who may have?  They could be a wealth of info.

I cheated. I read an article prior to Alfred's (66andblue) article. The horns contain a lot of proprietary parts that are simply unrestorable to mortals, but maybe to "makers" that like to fabricate things. I decided that completely accurate restoration was beyond what I started with. Onto "Plan B."

So, what I did was disassemble the horns, throw out the "guts", powder coat the clamshell cases, and install a new smaller Bosch SEALED horn within. Re-assemble with a Stoddard Motors kit. New tags. They came out beautiful, they sound great (though not the absolute perfect pitch) and look like jeweled treasures. Thus they never made it back onto the car! I couldn't do that to them. Living 6" from the ground, subject to all manner of road debris and water, would render them ugly too soon.

[Merc_Girl]

Thank you

I think I can get a copy through the members area

I’ll take a look, thank you 

[rwmastel]

Hello Katie,
in Pagodaworld 21 (2017) I described the testing and tuning process that might be helpful to you. Do you have access to the article?

I think I can get a copy through the members area

All the Pagoda Notes are available through Full Membership.  None of the Pagoda Worlds are.  Those are being compiled into the books and sold.

[Merc_Girl]

Thanks Rodd for clarifying 😁