'07 RSV Horn wiring---I'm so-o-o-o confused!!!

[Mel]

I am contemplating changing to different electrical horns and relocating them. In preparation I am checking the wiring for polarity, on/off with the ignition, etc. I am accessing the right side horn. You know, the one that they have aimed right at the exhaust! I expected to find the pink wire hot with the key on, but I find both the pink and brown wires to be hot when the key is on. I have looked at the wiring diagram, guess I just do not understand how the horn button makes these OEM horns work. I expected to be able to ground the after-market horns and connect a lead to the other connector that would become hot when the horn button was activated. OR I would hook up a lead that was hot when the key is on and the other connector would go to the horn button and be grounded when the button is activated. With both leads testing hot with the key on I am lost. I know one or more of you wizards can explain this to me and point me in the right direction. For clarification, I want to install a pair of compact boat horns out front (106 db each). I know most of you prefer the air horn, but this is my story and I'm sticking to it. Thanks for any help I can get.

 

Mel

[Eck]

The wires going to the horn will NOT be HOT until you turn on the key and then HIT THE HORN BUTTON..the juice has to pass through the horn relay first

[Mel]

Eck

 

Then why do they test hot (light up my 12V test light) when the key is on and I am not activating the horn button? Some kind of feed-back from the other horn?

[Guest human4m]

I ran into a similar issue when I was going to install my Wolo horns. I hooked up the wires (in a hurry) and as soon as I turned the key on, the horn was BLARING without touching the button. I figured I had something crossed somewhere (amongst all two wires) and had places to go, so I just stuck the stock wimpy horn back on.

[Ponch]

I ran into a similar issue when I was going to install my Wolo horns. I hooked up the wires (in a hurry) and as soon as I turned the key on, the horn was BLARING without touching the button. I figured I had something crossed somewhere (amongst all two wires) and had places to go, so I just stuck the stock wimpy horn back on.

 

I think you grounded one of the terminals on the the horn which completed the circuit bypassing the relay. The horn button completes the circuit to ground (pretty sure).

[Scooter Bob]

From the looks of the wiring diagram, both horns have power supplied from the signal fuse on the brown wire. The pink wire runs from the other side of the horns to the switch. The switch is then used to complete the circuit to ground. This is why you see power on both wires, although the pink is probably a bit lower voltage due to the resistance of the horn coil.

 

Since these new horns probably draw higher current, you should probably use a 12 volt relay with the coil terminals wired in place of the horn, brown and pink. Then run a larger fused wire from the battery to one side of the switched terminal on the relay and connect the horn positive to the other side of the switched relay terminal. Ground the horns to chassis and you'll be all set.

 

Any more questions, let me know, Scooter Bob

[Eck]

The wires going to the horn will NOT be HOT until you turn on the key and then HIT THE HORN BUTTON..the juice has to pass through the horn relay first

 

 

Please forgive me but I may be wrong with my above statement. I should not have provided and answer since I really am not sure. I posted what I "thought" to be true and it may not be gospel.

[wes0778]

Lets break it down very simply. For example only forget the bike's system and just think of a very simplified electrical circuit. It will start from the positive post of the battery. A wire runs from there to one terminal on the horn. From the other terminal of the horn a wire runs to one terminal of push button switch which has to be pushed to make connection between the two terminals of that switch. From the other terminal of the push button a wire is run to the negative post of the battery. When you push the button, the circuit is completed and the horn blows.

 

Now to relate this to our bikes (RSVs and RSTDs). The horn button on the handlebar is the same as the push button mentioned above. It completes the circuit to ground (the negative battery terminal). That is the part that confuses some folks who are used to a switch sending positive voltage to a component, like the horn.

Back to the bike, when the key is turned on, the system sends voltage, full time, to one terminal of the horn (there are two horns on an RSV, not sure about the RSTD) via the brown wire. The pink wire runs to the horn button. Some confusion is generated by trying to check voltages when only one horn is unplugged.

If you are going to install after market horns of any kind I feel it would be prudent to add a relay to control them, as the factory wiring will not handle much additional load. Of course THAT opens a whole different discussion.

[V7Goose]

As others here have already stated, the stock horn button provides a ground to one of the horn terminals, the other terminal is always hot when the key is on.

 

Adding a horn relay to the stock wires could not be any more simple:

 

1. Unplug the wires from the stock horn.
   
2. Plug the same wires onto a standard 30A horn/light relay - just split the two plugs apart and put them on the relay coil terminals - it makes no difference which wire on which side of the coil. Now the new relay will energize when you hit the horn button.
   
3. Run a 14 gauge wire from the battery positive terminal to either of the relay contact terminals.
   
4. Run a 14 gauge wire from the other relay contact terminal to the + terminal on a horn.
   
5. Run a 14 gauge wire from the ground terminal on a horn to the frame or engine ground.
   

You do not have to disconnect the other stock horn to do this, but is is a good idea to do so. If you want to leave it operational, I'd suggest running a new 14 gauge wire from the new relay to the second stock horn, and a new 14 gauge wire from that horn to ground. This will ensure the maximum voltage and current is delivered to both horns.

 

The relay can be mounted near either of the stock horns, but it is easiest to do it with the rear one. A perfect place to mount the new horn relay is inside the Right side battery cover, just in front of the carb heater thermo switch - it will fit there perfectly and stays dry.

Goose

[Nemo]

Mel, you are getting a "hot" reading on both wires at the horn because the actual "hot" wire is going through the horn windings, which makes the other wire appear as "hot" also. Just disconnect the wires from the horn. Then when you check it now, you'll find that just one wire is the "hot" wire. The other wire will check as dead, until the horn button is pushed and then it become a negitive test.

[wes0778]

Mel, you are getting a "hot" reading on both wires at the horn because the actual "hot" wire is going through the horn windings, which makes the other wire appear as "hot" also. Just disconnect the wires from the horn. Then when you check it now, you'll find that just one wire is the "hot" wire. The other wire will check as dead, until the horn button is pushed and then it become a negitive test.

 

Don't forget disconnect both horns!!!

[bongobobny]

, although the pink is probably a bit lower voltage due to the resistance of the horn coil.

 

No, both sides will be exactly the same voltage reading because no current is being drawn, therefore no IR drop..

[Nemo]

OK Mel, I apologize - now my face is really red! I forgot about that other horn. Sorry 'bout that! Owen