Fixing a horn

[bbap]

got her apart. I don't see anything obvious. I see that there is a points-type connection. It is presently in the "Closed" orientation with the spring holding it there. I pulled the stud and opened them slightly and drew a small piece of 1,000 grit sandpaper through them. Any other suggestions?


Honda Dream 305 Horn by krt3306, on Flickr

[bbap]

Found the problem. In my case I needed to clean up the points better than I thought. I ran some 220 grit sandpaper on the top and bottom of the contact area under spring tension about 6-7 times. I reconnected to battery and it sounds perfect.

I reconnected to the frame and did the same - all good
I reconnected the harness back to it and used the push button - feeble and intermittent. I suspect a button problem which I will investigate further.

[jleewebb]

yours is different than mine, but they all work pretty much the same. I'd advise looking it over, figuring out exactly how it works, and maybe it'll come to you.

basically, with points closed, the coil pulls or pushes the diaphram in one direction or the other. movement of diaphram opens points, cutting current to coil, leaf spring pushes it back the other direction, closing points, energizing coil, and starting cycle over.

at some point in there I'd test continuity with points open and closed, then explore further electrically if necessary.

good luck, Lee

[conbs]

If you do not have a good ground at your horn button or strong current in your hot wire, your horn won't work well. Corrosion, loose connections, shorted wire, etc. in your horn button, connectors or even your key switch will keep you from getting a good solid 12v current to your horn. Feeble power = feeble horn.

If your points are out of adjustment that can make a feeble horn, too. Think of it like adjusting your ignition points. If they are right your motor runs better. If the little screw in your horn is adjusted right, the horn will work better. Give it a good 12v source across the 2 wires and make minute adjustments at the screw until it makes the loudest sound you can get out of it. It has to be closed to start the horn diaphram cycling as Lee has described, but you want the diaphram moving as far as possible to give the greatest resonance.

You may want to try 400 grit sandpaper on the points or an ignition points file. It needs to be pretty smooth. A lot of current goes through those points and if they are burnt or sticking together, the horn won't work well. You don't use your horn much so if you get them smooth, the points should give good service for a long while. Still, after 40 or 50 years we all get a little crusty.

In spite of its simplicity, your horn is delicate. No hammers. If there is any corrosion and you can get it out mechanically, do it. Spraying WD40 and other chemicals will make a mess and your horn probably won't work as well when the dirt starts sticking to it.

Hope this helps you get your horn working well.

[dagersh]

Hi Guys!

Great thread!

Quick question - just killed the battery (ooops) so i can't yet adjust the horn - however, the bar is moving with a press of the switch.

However, when I was moving the slottede adjustment screw, nothing was happening. I am hoping my voltage was low, so I was not getting a honk.

How is that for a theory? I will update as soon as the battery is back at full juice.

Gersh

[giuliettashop]

A very basic question... How do I get the cover off the horn?

[LOUD MOUSE]

Which bike do you have?. ........lm

A very basic question... How do I get the cover off the horn?