anything servicable inside old car horn?

[steveo3002]

bought a old yank 50s car horn and it doesnt seem to work

wondered if theres anything inside fixable etc

no big deal but id like to use it

 

[rtbcomp]

If it works on the bell principle it will have a pair of contacts that can be cleaned/adjusted.

If the coil is burnt out it could be rewound.

 

[steveo3002]

ah ok...the casing is crimped over in places but i think i cant get it apart

i get the odd grunt when i touch some wires on it

 

[rtbcomp]

I'd go for a contact clean then.

 

[ronan]

Email taff the horn,

http://taffthehorns.com/

 

[steveo3002]

see anything here? the contact points are touching with it at rest?

 

[rtbcomp]

The contacts should be closed at rest, when you apply power the coil opens the contacts, and as they are in series with coil, they close again and so the cycle repeats.

The coil is attached to a diaphragm which is what makes the noise.

I suspect there should be slight clearance between the nut and the arm connected to the bottom contact, this will allow the diaphragm to get moving before the contacts open.

 

[steveo3002]

any suggestions what to poke at to get it going? points look clean enough

 

[rtbcomp]

Loosen the nut off slightly. I take it it's a 12v horn?

Push down on the nut, you should see the contacts open.

 

[steveo3002]

yes its marked 12v

 

[steveo3002]

right cleaned up the points ..tried ajusting the nut which i assume just alters the tension on the points?

still no further forward...the center of the horn moves a few mm and i get a slight grunt

anything else i can try...no idea how old or what its off ...i wouldnt need to earth the body as well would i?

 

[rtbcomp]

The nut adjusts the tone.

If it's slackened off the diaphragm has to move further before the contacts part, this takes longer and you get a lower note.

If the nut is too slack the points will never open, giving a click, if the nut's too tight the points won't close and the coil will not get energised.

If you're connecting the battery to each end of the coil you may be bypassing the contacts. Are one side of the contacts earthed to the case? If so connect the battery between the case and the end of the coil that doesn't connect to the contacts.

Connect a 15A fuse in one of the battery leads in case you manage to short it out.

 

[steveo3002]

messed around with it for ages and still nothing..so i roared some penetrating oil up it and its working now lol

cheers

 

[rtbcomp]

That's good.