Horn

[Elio]

I have just installed a double horn which seemed to work fine. This morning on arriving at work I switched the engine of and then tried to start it again with no response at all. I assume that the new horn(S) have caused some kind of fuse blow. Can anyone please advise?

Thanks

Elio

:(

[Baph]

In all honesty, it depends entirely how you wired it up. Did you use the stock wiring? Did you use a relay?

Could just be that one of the connections has worked loose.

Post back with details of how you wired it up.

[Elio]

I wired it to the existing cabling and then just looped the second horn off of that one

[Baph]

Ah, bad move. You might of fried something more serious than a fuse.

Right, from the wiring diagram:

The horn itself is negative switched (meaning there's always a positive feed to the horn, and the circuit is completed when you hit the button).

The positive feed itself comes from the front brake switch, the neutral light on the dash, the engine temperature warning light.

The first point this lot is "fused" at, is the indicator relay. Check that your indicators still work, and both the lights above (engine temp you probably won't be able to check unless you manually give it 12v).

Check that your headlights (including PASS) still works.

The most likely fuse to of gone, if fuse 4 in the fusebox. Other than that is the main one, which is 30A. If this is popped because of the horn, I'd be very supprised if the rest of the bike survived.

There's probably a fair bit that I haven't seen on the diagram that could of been effected too, even down to the wiring loom connectors. I'd look very closely at the bike before taking it out on the road again.

Where you wired the horn in, take the horn out, put a relay there (the coils of the relay (85 & 86 on a bosch style relay) where the horn was), then run +ve & -ve from the battery/frame through the relay to the horn.

If you need help in any more detail, post back or drop me a message.


EDIT: Also, what horn did you fit? As this will give a clue as to the damage because of the max current rating.
HTH.

[Elio]

thanks

[Luckypants]

Did you use the horn this morning? Just to be clear if you might have fried the wiring or something by using it?

Also did you check your new wiring to see if it touched any thing hot to melt the insulation or has rubbed on something to expose the wires? This might have caused a short.

Else wait for Baph the electrical wizard....

[northwind]

Yup, it shouldn't have caused any problems if it wasn't used... Unless you've wired the battery terminals together or somesuch ;) Do the dash lights etc still come on? From memory the horn is in a circuit that has assorted lights and maybe instruments on, but not the ignition, so unless it's weirdly wired or it's taken the 30A fuse out it'd be strange to cause a non-starting fault.

The horn's the obvious suspect but don't rule out other faults/issues. This includes making sure the killswitch isn't on ;)

[Elio]

Thanks guys. It seemed to have blown a couple of fuses. I have replaced them and disconnected one of the horns. Hopefully one horn will be ok

I'll let you know

Elio

[Elio]

can you let me know where the 30amp fuse is as I am not familiar with it just in case it blows the other fuses again

[Baph]

Thanks guys. It seemed to have blown a couple of fuses. I have replaced them and disconnected one of the horns. Hopefully one horn will be ok

I'll let you know

Elio

Don't be so sure. There's a reason that the stock horn is so much quieter. It draws less current. There's a pretty serious risk of doing serious damage to the bike's electrics if you continue to run (even one horn) the way it's wired up.

I strongly advice you put a relay in there. But in saying that, others run loud horns without a relay. Your bike, your choice. I personally use a relay.

The main fuse on the curvy's, IIRC, is on the right side of the bike behind the side plastics? In a green cover? I'm sure someone with a curvy will be able to tell you better.

[Elio]

Am I being stupid in thinking that if you replace a 12v horn with a 12v horn the current drawn should be the same?

Elio

:confused: :confused:

[Luckypants]

Don't be so sure. There's a reason that the stock horn is so much quieter. It draws less current. There's a pretty serious risk of doing serious damage to the bike's electrics if you continue to run (even one horn) the way it's wired up.

I strongly advice you put a relay in there. But in saying that, others run loud horns without a relay. Your bike, your choice. I personally use a relay.

Ditto

The main fuse on the curvy's, IIRC, is on the right side of the bike behind the side plastics? In a green cover? I'm sure someone with a curvy will be able to tell you better.
Correct! :rolleyes:

[Baph]

Am I being stupid in thinking that if you replace a 12v horn with a 12v horn the current drawn should be the same?

Elio

:confused: :confused:

They will still use 12v, however, the stock horn could be as little as 3A. A replacement horn could take 30A or more (depending on the horn).

EDIT: In fact, the stock horn draws 3.3A, I have the Stebel Magnum fitted, and that's rated at 12A, definately more than enough to pop a 5A fuse.

[Luckypants]

Am I being stupid in thinking that if you replace a 12v horn with a 12v horn the current drawn should be the same?

Elio

:confused: :confused:
not being stupid unless you ask twice. ;)

The amount of noise the horn makes depends on how powerful it is, agreed? A 110 Db horn is more powerful than a 90Db horn, agreed?
Where does the extra power come from? In DC electrics Power = Voltage x Current. As the voltage is always 12, then to increase power you muct increase the current. So the more powerful horn will draw more current.

[Elio]

Is a relay easy to install and do you have any documentation or is it a garage job for the beginner?

[Luckypants]

Yes it is. There are some instructions on the main SV650.org site, in the FAQ section - titled 'how to fit Fiamm Twin horns' or something similar. Is a Word document with full instructions.

[Baph]

Is a relay easy to install and do you have any documentation or is it a garage job for the beginner?

It's absolutely pish.

Pop along to your local Maplin & ask them for a 40A automotive relay (if they don't have any in stock a 30A will do too - I just always use 40A). That is a bosch style relay. You'll also need some wire whilst you're there. Anything that's 2core and can cope with 15A should do fine for a horn. 2m is overkill, but better to get more than be caught short.

Where you have (or had) the horn plugged in, connect these wires to the pins marked "85" and "86".

Your new wire, put an eyelet on (that's the right size), and stick this into your +ve battery terminal. Run the wire to the relay, and plug this into the pin marked "87". Next, run another wire from the pin marked "30" and take this to the horn. From the other pin on the horn, run this to the bike frame.

Done. Turn the ignition on, hit the horn button, and crap yourself because it's so loud!! Oh yea, find somewhere to mount that relay & glue it in place (on the airbox is as good a place as any).

[Luckypants]

It's absolutely pish.

Pop along to your local Maplin & ask them for a 40A automotive relay (if they don't have any in stock a 30A will do too - I just always use 40A). That is a bosch style relay. You'll also need some wire whilst you're there. Anything that's 2core and can cope with 15A should do fine for a horn. 2m is overkill, but better to get more than be caught short.

Where you have (or had) the horn plugged in, connect these wires to the pins marked "85" and "86".

Your new wire, put an eyelet on (that's the right size), and stick this into your +ve battery terminal. Run the wire to the relay, and plug this into the pin marked "87a". Next, run another wire from the pin marked "30" and take this to somewhere on your bikes frame. I find faring bolts work nicely for this.

Done. Turn the ignition on, hit the horn button, and crap yourself because it's so loud!! Oh yea, find somewhere to mount that relay & glue it in place (on the airbox is as good a place as any).

Baph! I think you just told him how to wire a short circuit using a relay! The horn switch wires go on 85 / 86.

The wire from Battery to 87A Ok, then wire from 30 To THE HORNS then earth the horns to the frame?

Shoot me down if I'm wrong

[Baph]

Baph! I think you just told him how to wire a short circuit using a relay! The horn switch wires go on 85 / 86.

The wire from Battery to 87A Ok, then wire from 30 To THE HORNS then earth the horns to the frame?

Shoot me down if I'm wrong
Apologies, duly corrected.

Also, it wouldn't really short circuit... but it could make for an interesting way to make sparks (which if wired up where mine is would be around the riders groin :D )

[Elio]

Thanks for all the help

Elio

[Elio]

One more question guys. Do I need to have a fuse between the battery and the relay?

thanks

Elio

[Luckypants]

I have one on mine. Just protects the battery from a short circuit if the wiring goes west or water shorts out the relay. Think it's a 10 or 15 amp in line jobbie. I have twin fiamm horns.

[Elio]

Thanks

Elio

[northwind]

A fuse is good common sense really. Halfords sell a wiring kit for horns and lights, containing a relay and wiring. It's ****, but does make it a little easier. Buying or borrowing a crimp tool would be handy.

I keep on meaning to check the draw of the FIAMM horns, and the flat FIAMMs, I've been running one FIAMM snailshell on the stock wiring without mishaps but it's not good practice at all.