Horn Trouble

[chuckycheese]

OK, all you experts, here's the problem!!
I bought a new horn for my bike and it sounds great while the bike is idleing in the driveway, but......on the road, it sounds weak and unsteady. I don't think the vibration is causing a problem and the wiring seems to be fine but the best tone I ever get is when it's standing still. I can even rev it up and it still works great. I feel sure the problem is simple but I don't know what it might be. I will appreciate your thougts!!

[argonsagas]

Sounds like you may have the horn mounted very close to the frame, and at speed it is flexing back just enough to contact the frame where its necessary vibration is being damped.

If this applies, the cure is simple: try changing the position, or put a spacer behind, to give it a bit more clearance.

If not, wait a bit. I'm sure more suggestions will follow...

[KrazyKarl02]

You may also want to clean out the contact on the horn switch

[chuckycheese]

Thanks

Well, thanks, so far. It's not touching the frame and....remember, it works great when the bike is sitting in one spot; even going through considerable vibration when revving up so....I'm stumped. I think it's got to be some kind of electrical problem but it must be more complicated than grounding.

[argonsagas]

It appears your only other option is wiring.

Back to the flex idea

You have two very thin wires running to the horn, one live and one ground. One is live as long as the ignition is ON, and the ground goes to your horn switch.

Check the terminals, but also check the wires themselves...they are very small and subject to breaking internally. You may find the strands inside one or both have mostly broken, and now make intermittent contact as the wire flexes in the wind.

This would usually happen at or near the terminals, so replacing or refastening the terminals may be what's necessary.

Even if a few strands have broken, this could apply, as there isn't much there to begin with, so the few remaining bits may not be able to carry the current needed to blow the horn.

Splicing the wires all the way back requires opening up the harness, and that is time-consuming as the splice inside the harness is back about ten inches. (The splice is to the orange/white wires that power the signal lights.) If you make an external splice, do it close to the harness and tape the new one(s) to it for an inch or so.

Having had the experience, I would leave opening the switch as a last resort, because there are tiny parts inside it that just love to jump out and disappear.

If you do it, it's probably best to have a large clear plastic bag around it and work inside the bag while looking through it.

[Anonymous]

I believe Roy is on the right track about the thin wires. I had the same problem. Bought a new horn, and still had the same problem. I took the easy way out. There was enough current to operate a relay, which was wired directly to the battery terminals. Now my horn works perfectly.

Erik