Tokairika 374-6 lhs switch.

[Brendan W]

I have the rocker type horn button lhs switch that I want to replace as it's seen too many repairs and I'm losing volts.
I picked up a clean looking Tokairika 374-6 switch with the round push button horn. It was fitted to an 850 L. Everything checks out except the horn. I've cleaned it thoroughly down to every track, spring seat and ball but can't get that horn contact to close. It feels like the button spring is binding coils before the contacts meet. Anyone with experience of these switches.

[Nessism]

Going off memory but I seem to recall the horn switch mechanism is very simple. It's the turn signal mechanism for the auto cancel system that's complicated. The horn contact should be made long before any coil bind.

[geol]

The switch for a button horn is a piece of rounded copper fitted into the plastic button. The contact is two parts; inner part that contacts the rounded copper button piece allows contact and the spring itself is what allows power to move through to the horn directly or through the clutch interlock switch. Open your headlight shell and by pass the switch by finding the two yellow/green wires that are NOT associated with the clutch interlock switch and plug them together; effectively bypassing that switch. This will take out one possible problem area.

Inside the headlight shell you can also check for voltage with the key on and horn button pushed. If no voltage here, then go back to your horn button and clean the copper spring. The one on my horn button wouldn't conduct voltage till I cleaned it... a little emery board and a wire wheel on my drill. If you do have voltage here, it is time to test your horn. Take off the leads from the wiring harness and connect two wires to the leads. Now touch these leads to the battery terminals. If it doesn't blow, the horn itself is the problem. If it blows, there is a problem with wiring between connector in headlight and the horn itself as there are no other connectors and this is unlikely I would guess.

[Brendan W]

Thanks again guys. Issue sorted and it was the spring and copper button insert contact point. It was doing my head in because I thought I had cleaned everything and was right in at the power and earth wires on the back of the board and nada.
It's not enough to clean the ends of the spring. That top-hat copper pole in the button is slightly tapered and looks like it's the inside of the spring coils that make the primary contact.
Thanks for you interest and time in replying.

[geol]

Glad to hear it! I was stumped on this for quite awhile. I had cleaned both sides of the button contact (the top hat thing and the other side) and still nada until I cleaned the spring. It was a tad brownish but didn't look to bad but it sure wasn't conducting! Good luck with your bike.