I just got a couple of original horns and both seem to be inoperative(hooked them directly to the battery to test them) Does anyone know if they are rebuild able and how? I made a half-hearted search of the forums and came up dry.

Thanks,

H Houghton

I just got a couple of original horns and both seem to be inoperative(hooked them directly to the battery to test them) Does anyone know if they are rebuild able and how? I made a half-hearted search of the forums and came up dry.

Thanks,

H Houghton

Norm in Vancouver BC has a web sight at www.zeddsaver.com and advertises rebuilt horn for sale. He may be able to advise you, if you can get ahold of him, or work out something with yours as a core charge for his rebuilt horns. Good luck.

Dan

I haven't rebuilt Datsun horns, but I have rebuilt the horns on an early MGB, which looked much the same. If the horn can be disassembled (screws or rivets holding it together), you should be fine to rebuild. Because generally all they need is to be disassembled and thoroughly cleaned. There's not much in there to wear out.

Electrical horns will have an adjuster on them somewhere to optimize the tone, either a screw with locknut or perhaps a bendable contact arm.

Some have it external to the works, others you have to dissemble to get to it.

The principal is similar to a set of ignition points.

A set of contacts are operated by the electro-magnetic operation of the diaphragm.

Usually, the points get dirty or burnt and prevent the coil from energising correctly.

They also have a resistor across them to quench the back EMF from the coil when the points open.

This is designed to prevent the points from arcing during operation.

Check to see if it is still intact and effective.

From memory it is ~200ohm.

You can see the contacts and spark quench resistor in the schematic attached.

This horn requires dissembly to get to the adjuster.

I never had mine apart. I only stripped the outside & repainted. Isn't there supposed to be a tuning nut in the center?

thxZ

Beauty, I knew I could depend on ya'll.

I will disassemble tomorrow and have a look.

Best,

H Houghton

If your horns used paper "gaskets" to cushion the diaphragm it's important that you don't forget to re-use or replace them. Don't re-assemble without as that will really affect the tone of the horn.

Also don't be surprised if you have to re-tone the horn after disassembly. That happens often because you changed the stress on the diaphragm and it can now contact or not get close to the magnetic coil.

FWIW

E