Horn Help

bigdog · Oct 13, 2024

I replaced my handlebars with some regular bars and risers, and now the horn does not function
It appears to have a Denali Air horn, with the compressor under the seat. It looks like the PO tapped into power near the battery (there is a fused link and what appears to be a ground wire headed toward the battery and terminating in a Relay with several wires running toward it. I assume it is a relay for the air horn to use the stock horn switch?? . The actual DEnali horn is located on left side behind lower panels.
I am a horn newby, don't know shit about relay except how to change them, and electrical stuff in general makes me feel kinda stupid.
I tried to find a Denali install page that correlates to this install but no luck.

Hell, I don't even know where the original horn is located and how to understand the wiring diagram. Where was the original horn located and what color wires where attached to it? I have Mini sound bomb laying around I would gladly swap in there to make things simple. I don't want to be taking those panels off more than once for this fix

So, before I take off all the panels I would love a little tutorial or advice on steps to take to see how to diagnose this issue.
The one thing I did was take the handlebar switch apart to see if there is power to the two wires controled by the switch: NO POWER There

No suggestion is to simple or novice for me in this area. Thanks in advance

RossKean · Oct 13, 2024

If I am not mistaken, the horn is on the hot side and the horn switch completes circuit to ground?
Horn(s) are mounted by the upper part of the radiator and to one side or the other (or both). Gen I and II have two horns but at some point, Yamaha went to a single horn on one side Gen III+). I went to PIAA Slimline Sports horns for decent volume without the obnoxious (and failure-prone) air horns. Two of them can run off the normal horn circuit without using a relay but you will need some sort of wiring harness if you do it. Check the horn by direct connection to 12V. Check the fuse. Check that the switch works.

YouTube of someone who added PIAA horns to a Gen III...

infrared · Oct 13, 2024

I would expect power at the switch. For that, I would consult the manual and check fuses. You say there is an inline fuse for the horn, and probably the stock fuse where it should be.

An electromagnet is a coil of wire. Put a Voltage on the wires from each end of the coil, and it becomes a real magnet, but it's a magnet that you can switch on and off. A relay is just an Off-On switch that can easily handle a grundle of power. You can't flip that relay switch with a finger, but if you turn on the electromagnet, then magnetism will pull an iron rod connected to the switch. That rod will flip the heavy-duty switch. It takes very little power to make the coil into a magnet, so even a lightweight little switch can flip on the relay. Any switch on a bike (that does something now without a relay) will last about forever if it is used to turn on a relay coil, instead of the original heavy load. Replacing a stock handlebar switch can cost a mint, and that's if you can still buy one. A common relay may cost less than US$ 5 and is available at most auto parts stores. If your handlebar switches power relays, then those expensive handlebar switches will outlast the bike. Any relay failure is cheap and easy to fix. At home, a relay controlled by a little switch (such as found in the home thermostat) will be turning on your home furnace or air conditioning system. No lightweight switch could carry that load, but the switch inside the relay is built heavy enough to do that.

Hope that helps. It would help us to help you if you put your FJR year and model in your signature, or under your avatar. Still, there is no telling what the PO did there, so you will be stuck for tracing out the install. If you are located near a forum member, they may be able to come by to lend a hand there. Can't hurt to ask, and make the arrangements by Private Messages.

vzhq16 · Oct 14, 2024

bigdog said:
I replaced my handlebars with some regular bars and risers, and now the horn does not function
It appears to have a Denali Air horn, with the compressor under the seat. It looks like the PO tapped into power near the battery (there is a fused link and what appears to be a ground wire headed toward the battery and terminating in a Relay with several wires running toward it. I assume it is a relay for the air horn to use the stock horn switch?? . The actual DEnali horn is located on left side behind lower panels.
I am a horn newby, don't know shit about relay except how to change them, and electrical stuff in general makes me feel kinda stupid.
I tried to find a Denali install page that correlates to this install but no luck.

Hell, I don't even know where the original horn is located and how to understand the wiring diagram. Where was the original horn located and what color wires where attached to it? I have Mini sound bomb laying around I would gladly swap in there to make things simple. I don't want to be taking those panels off more than once for this fix

So, before I take off all the panels I would love a little tutorial or advice on steps to take to see how to diagnose this issue.
The one thing I did was take the handlebar switch apart to see if there is power to the two wires controled by the switch: NO POWER There

No suggestion is to simple or novice for me in this area. Thanks in advance

What year and model are we talking about?

bigdog · Oct 14, 2024

My bike is a 2016 ES model. 11,400 miles

vzhq16 · Oct 14, 2024

bigdog said:
My bike is a 2016 ES model. 11,400 miles

Ok, the horn button gets power from the signal fuse. If the fuse is bad, your signals won't work either. Lets start there. Do the turn signals still work? If not, to check that fuse, you'll only need to remove the cover over the battery ( 2 screws and 2 push pin rivets). You can use the 4mm hex wrench to pop those body rivets unlocked. Have you worked with those before? The signal fuse is a 7.5A fuse in position 9. Hope this helps!

bigdog · Oct 14, 2024

Turn signals are operational! I think I am ready for start taking panels off, and perhaps just to back to a regular horn, PIAA or other.

infrared said:
I would expect power at the switch. For that, I would consult the manual and check fuses. You say there is an inline fuse for the horn, and probably the stock fuse where it should be.

An electromagnet is a coil of wire. Put a Voltage on the wires from each end of the coil, and it becomes a real magnet, but it's a magnet that you can switch on and off. A relay is just an Off-On switch that can easily handle a grundle of power. You can't flip that relay switch with a finger, but if you turn on the electromagnet, then magnetism will pull an iron rod connected to the switch. That rod will flip the heavy-duty switch. It takes very little power to make the coil into a magnet, so even a lightweight little switch can flip on the relay. Any switch on a bike (that does something now without a relay) will last about forever if it is used to turn on a relay coil, instead of the original heavy load. Replacing a stock handlebar switch can cost a mint, and that's if you can still buy one. A common relay may cost less than US$ 5 and is available at most auto parts stores. If your handlebar switches power relays, then those expensive handlebar switches will outlast the bike. Any relay failure is cheap and easy to fix. At home, a relay controlled by a little switch (such as found in the home thermostat) will be turning on your home furnace or air conditioning system. No lightweight switch could carry that load, but the switch inside the relay is built heavy enough to do that.

Hope that helps. It would help us to help you if you put your FJR year and model in your signature, or under your avatar. Still, there is no telling what the PO did there, so you will be stuck for tracing out the install. If you are located near a forum member, they may be able to come by to lend a hand there. Can't hurt to ask, and make the arrangements by Private Messages.

Love that explanation! And I think I actually understand it. Strange that my horn switch does not show power, but maybe I am checking it wrong: Hold a lead from Voltage meter to both both wires inside switch (took it apart) and no power, with or without horn button (switch) held in.
Factory fuse seems good since turn signals are operational.

infrared · Oct 14, 2024

Bigdog,

Clip one lead to the negative battery terminal whenever you are checking for power.

bigdog · Oct 14, 2024

Lip one from the relay?

infrared · Oct 14, 2024

Bigdog,
Common car relay in the diagram. It just plugs into its' socket like a power cord. Connecting a wire to a socket pin is really connecting the wire to the same number pin of the relay. Any auto parts store can show you a relay-with-socket. The relay plugs into the socket just like any power cord plugs into the wall outlet.

Connect pin 85 to Ground.
Connect Pin 86 to the wire that brings power from the handlebar switch .
When you operate the handlebar switch, the relay will click.
Connect Pin 30 to battery power, 12Vdc usually. Get this power from the battery, or from the ignition switch/ fuseblock.
Connect Pin 87a to the gadget that is (was) run by the handlebar switch. If the horn sounds when you hit the switch, fine. If not, connect the horn wire to Pin 87 instead of 87a.
Now when you operate the handlebar switch, the relay coil becomes a magnet, and the heavy switch inside the relay makes contact. In this case, this relay is now a horn relay, The horn will sound, and stop when you release the handlebar switch.

Rogue · Oct 14, 2024

infrared said:
Bigdog,
Common car relay in the diagram. It just plugs into its' socket like a power cord. Connecting a wire to a socket pin is really connecting the wire to the same number pin of the relay. Any auto parts store can show you a relay-with-socket. The relay plugs into the socket just like any power cord plugs into the wall outlet.
View attachment 8298
Connect pin 85 to Ground.
Connect Pin 86 to the wire that brings power from the handlebar switch .
When you operate the handlebar switch, the relay will click.
Connect Pin 30 to battery power, 12Vdc usually. Get this power from the battery, or from the ignition switch/ fuseblock.
Connect Pin 87a to the gadget that is (was) run by the handlebar switch. If the horn sounds when you hit the switch, fine. If not, connect the horn wire to Pin 87 instead of 87a.
Now when you operate the handlebar switch, the relay coil becomes a magnet, and the heavy switch inside the relay makes contact. In this case, this relay is now a horn relay, The horn will sound, and stop when you release the handlebar switch.

Good description but use terminal 87, not 87a. 87a is normally closed (on when the relay isn't activated) and most automotive relays will just be normally open and not have terminal 87a.

bigdog · Oct 15, 2024

Seems like replacing relay is easiest place to start?

vzhq16 · Oct 15, 2024

Doing the tests is the easiest place to start. If you don't hear that relay "click" when you press the horn button with the ignition switch on, put one probe of a voltmeter on the 86 or 87 terminal and the other probe on a good ground point. Depending on how it was wired, you'll either see 12V when you press the horn button on one of those terminals or not. If not, the problem is "upstream". I believe RossKean and Infrared have a point about the way the system works. The horn button completes a circuit to ground so, you won't see 12V at the horn button. You can test to see if the horn button actually works by seeing if it completes a circuit to ground. There is at least one connector in the harness between the button and the electrical system ground. Make sure that is making good contact and clean. Keep moving upstream until you find where the break in the circuit is.

infrared · Oct 15, 2024

RossKean said:
If I am not mistaken, the horn is on the hot side and the horn switch completes circuit to ground?

If that is correct, then I believe your problem is simple. New handlebars caused it. You probably need to get a good ground to the handlebar switch. You need the bike wiring schematic to say which wire on the handlebar switch needs ground; do not guess.

Yamaha turns on other things on the FJR by putting ground on them, such as the brake light. The brake light always has power, but comes on only when the brake light switch puts ground on the brake light.

I would not tear anything apart until I got that much right.

graytaz · Oct 15, 2024

Maybe this diagram will help. I put it together when I installed my horns many moons ago and did the same on a friend's bike. I doubt that Yamaha has changed it from the Gen 1's and II's.

bigdog · Oct 15, 2024

Horn issue solved: Disconnected wire. It was really good to get in there and look at the wiring: Now I understand the electrical adds on so much better. Thanks to all that contributed!

bigdog · Oct 16, 2024

infrared said:
If that is correct, then I believe your problem is simple. New handlebars caused it. You probably need to get a good ground to the handlebar switch. You need the bike wiring schematic to say which wire on the handlebar switch needs ground; do not guess.

Yamaha turns on other things on the FJR by putting ground on them, such as the brake light. The brake light always has power, but comes on only when the brake light switch puts ground on the brake light.

I would not tear anything apart until I got that much right.

Yup, wire unplugged when I was installing handlebars. I redid all the taping and zip ties and tucked it behind a lower panel, all good now! thanks

vzhq16 · Oct 17, 2024

bigdog said:
Yup, wire unplugged when I was installing handlebars. I redid all the taping and zip ties and tucked it behind a lower panel, all good now! thanks

Glad you got it sorted out!

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