Quick horn wiring for Kristas question

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gregory

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Greetings,

I have installed a set of Kristas and have hooked up the full on bright to the high beams/flash to pass. I was getting ready to hook up the full on bright to go with the horn, but got a bit concerned with the fact that I have power to the horn without engaging the horn. As a professional at letting the smoke out of wires, I figured I better ask. I am assuming that pressing the horn button completes the circut by grounding it, as there is already power to the other side of the horn. (one side lights up the test probe and the other only lights up when I press the horn button.)

TIA,

Greg

 
Greetings,
I have installed a set of Kristas and have hooked up the full on bright to the high beams/flash to pass. I was getting ready to hook up the full on bright to go with the horn, but got a bit concerned with the fact that I have power to the horn without engaging the horn. As a professional at letting the smoke out of wires, I figured I better ask. I am assuming that pressing the horn button completes the circut by grounding it, as there is already power to the other side of the horn. (one side lights up the test probe and the other only lights up when I press the horn button.)

TIA,

Greg
Hold on...

FJR newbie here - but this doesn't sound right. The OP said:

"I am assuming that pressing the horn button completes the circut by grounding it, as there is already power to the other side of the horn. (one side lights up the test probe and the other only lights up when I press the horn button.)"

I would have thought that one side of the button is "live" all the time the key is on, and the other side is only "live" when the button is pressed. The side that is "live" when the button is pressed supplies power to one side of the horn, the other side of the horn is grounded.

Ok - this was posted in June 2014 - but just in case someone else reads it and then wonders why they get smoke.

 
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Hold on...FJR newbie here - but this doesn't sound right...
When the key is turned on +12 volts goes to both horns from the Signaling System fuse and will be 12 volts all the time. The other wire coming off the horns goes to the horn button.

The horn button has two contacts, one contact is connected to the horn wires, the other contact goes to a ground wire. Pressing the horn button bridges the two contacts together and grounds the horns, BBEEEEEPPPP.

So, you will find +12 volts at the horn button, and you will find ground at the horn button. 12 volts will go straight through the horn coils with no reduction because there is no path to ground until the horn button is pressed.

It is conventional electrical design to have switches and relays ground circuits and it is very rare for switching to supply power. An exception is when using a relay/switch to provide power to a fuse box or power distribution.

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The Brown wire is +12 volts from the Signaling System Fuse

The Pink wire is the side of the horn that will be grounded by the horn switch

The Black wire is ground

HornCircuit_zps93534447.jpg


 
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It's funny that this thread has resurfaced today, as I was finally getting around to finishing this job with a bunch of other prep for the Western FJR riders Roundup.

Don't know if my bike is an anomaly, but it came with only 1 horn (left side, same as horn button.). IIRC, Gen I and II had two horns?

I figured that power would be on one side only, and that I could tap into the opposite side and that would trigger the lights to full on bright when the horn is used and the circuit is completed.

WRONG! BOTH sides of the horn are "hot" with the key in the on position. Now, in the world of electrical knowledge, I am a 75 watt bulb (incandescent no less) in a 1000 watt world, so I checked the Clearwater website for guidance. As soon as I can find the "Addendum" for ground switching bikes, I will be in business!

Happy 4th everybody!

 
Connecting to the ground side of the switch would appear to address the issue.

It will get 12V when the switch is pressed.

Depending on how the dimmer is configured, you may need a diode in the line.

 
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Gregory

Take both horn leads off the horn, then test them. You will find that only one lead will be 'hot', the other lead will be dead - neither hot nor ground. That is the wire from the horn to the horn push button. When the push button is pressed it completes the electrical path back to the battery negative terminal via the grounding system. When this happens then electricity will flow and work will happen - hence BBEEEEEPPPP.

​What you will require is a way to convert the full time positive horn lead at the horn to a switched positive signal. This is done via a relay...

Tie the negative lead of the relay signal side (terminal 85) to the horn wire leading to the push button, the corresponding positive side (terminal 86) to an unswitched (fused) +12 volt. This same unswitched +12 volt is to be connected to the relay input (terminal 30), the Clearwater white wire attached to the normally open terminal of the relay (terminal 87). The normally closed terminal (87a) is unused.

neg2pos_zpsfb1ca5d3.gif


When the horn button is depressed the relay will trigger and you now have a horn button activated signal required for the Clearwater white wire.

Hope this helps.

Brodie

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Connecting to the ground side of the switch would appear to address the issue.
It will get 12V when the switch is pressed.

Depending on how the dimmer is configured, you may need a diode in the line.
Actually, it won't.

Here's the simplified horn wiring diagram

Hornwiringdiagram.jpg


The brown wire is ignition switched 12V from the Signal Fuse. It will remain 12V as long as the key is switched on regardless of the horn switch button.

The pink wire goes off to the horn switch and on the other side of the horn switch is frame ground.

If you put your voltmeter on the pink wire when the button is not being pressed you will see the 12V from the brown wire thru the horn. There will be no horn sound because you need to have current flow (not just voltage) for any work to be done.

If you kept the meter lead on the pink wire and then press the horn button the voltage will drop to 0V (in reference to ground) as you short that point to ground through the switch.

edit - Brodie's relay circuit above will allow you to create a switched 12V signal from the horn switch's being grounded when pushed.

 
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Thank you Gentlemen!

Your advice is both helpful and appreciated!

Brodie, how to cross paths again with you at the Roundup!

Greg

 
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So, here's a question for the Wire Wizards....

Does it matter where which wire, hot or ungrounded-ground, is plugged on the horns? I ***-u-me the horns aren't polarized??

 
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Howie

The horn has two tabs built in it for attaching wires. It does not matter if the pink wire and the brown wire get switched between the tabs. The horn will still work. On our dual horn motorcycle each horn needs to have a pair of pink and brown wires attached as per the diagram posted above.

Clear as mud?

Brodie

smile.png


 
Well, that's true that you can swap the wires and the horn will still work. But you'll want to make sure that you swap them on both horns, other wise the sound they put out will be phase reversed and tend to cancel each other out.

You wouldn't want that to happen, now would you? :rolleyes:

 
Don't bother. I was only joking. :lol:

Brought about by those audiophiles who believe that the same principle is true with speaker wiring: i.e. That if you wire one speaker backwards the sound will destructively cancel itself. Does it really? Not that I can tell... :unsure:

 
Put your stereo speakers face to face some time. Horns aren't speakers, they're DC door buzzers.

But you all knew that...

 
So, I tried it....wired up the horns "backwards" on my '04....brown wire on the left/pink on the right on the left horn, pink on the left/brown on the right on the right horn...pushed the horn button...there was a bright flash and this appeared in my garage

Asgard-LT.JPG


SO DON'T DO IT!!! HE DRANK ALL MY BEER!!

 
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