horn issue

Hi Nigel

Does your test lamp light up brightly or only dimly? If dim it probably isn`t getting enough current to kick the horn into life so suspect a poor contact somewhere in the circuit. More stripping and cleaning probably required.

Regards, Al.

I use a relatively low power air horn without a replay and it works, I stripped my handlebar switches many years ago, cleaned all the contacts and then applied silicone grease. Its this treatment I put down to having a working horn. If you do fully strip the handlebar switches do it inside a clear plastic bag so all the flying springs and ball bearings are retrievable.

Would be a quick an relatively easy start. As I remember the horn is connected to the battery on one terminal and the switch in series with it grounds the circuit to energise the horn.  You know the horn works so it’s probably your grounding circuit that is giving issues. Connect a lead to the grounded side of your battery , touch it on the grounded side of the horn.  horn sounds? That has prove your voltage is present.  (If not you need to look at your wiring to the horn). 

Now work your way towards the switch; connect the lead to the components of the machine and press the switch, the frame, the headstock, the handlebars the grounded part of the switch.  At some point the horn will sound, then you will have discovered the high resistance point in your circuit.

Grounding to the handlebars can be improved by running a lead from the switch point into the headlamp nacelle and picking up a ground point there.

Happy Christmas!

Jon

Hello Nigel,

It may help if you adjust the horn current consumption as per the factory manual.

Also fitting a relay unit reduces voltage drop.

Here is a link to some factory manual pages and photos of my horn repair.

 https://photos.app.goo.gl/SirkCUG6USzg8QrK8

I got carried away a bit and fitted twin horns tho...

Good luck.

.small detail but soldering bullets is not the best solution.  By holding each strand solid with solder the potential for cracking is high. Overspill from thorough soldering can reduce the surface contact area.  Using the correct crimp tool it’s a more secure method electrically.

Problem solved regardless.

Best regards

Jon

.. in 50 years of soldering bullets had the cracking you mention. Bullets were always originally soldered not crimped.

Being a fixer of electrical faults that come my way quite a bit, we do find that bad soldered bullets is not uncommon. The heavy weight crimp tool (bit expensive) seems to give a better result. While I favour the F crimp which is the preferred system used on the Commandos and Triumphs in the 70s/80s. Quite easy/quick to do. I think the badly soldered bullet is the result of lack of due diligence when soldering, which is a fine art not to be taken lightly.

My experience with older wiring is that soldered solutions were more after market.  Strand over, and crimped seem more prevalent, although many had subsequently been soldered.

Different point of view, but I’m sure both are suitable done correctly.    

Cheers

Jon

... that soldering is a skill which takes time & practice to perfect, but once mastered is a very satisfying method. And the principles are the same whether electrical connections or cables etc. I don't think crimping appeared until the 1960s at the earliest but would be happy to be proved wrong.

I believe that pre-war wiring connections were different again but have never actually seen any.