Signalling Fuse

[Buffaloears]

My signalling fuse (7.5 amp) blew - probably because I was going to replace the stock horn and tried to test the two wires to see which one was the hot lead and I must have somehow shorted them out and blew the fuse. I didn't have a 7.5 in my inventory so replaced it with a 10 amp fuse. Okay move? Bad move?

I'm wanting to repace the stock horn with PIAA double horns and I've seen some posts stating that you need a relay, while others say it's okay to wire them together. I watched a UTUBE video where he wired them together and said they work just fine.

Any suggestions would be greatly appreciated.

 

[Ignacio]

I didn't have a 7.5 in my inventory so replaced it with a 10 amp fuse. Okay move? Bad move?

I'm wanting to repace the stock horn with PIAA double horns...

Do you know the size of the wire on that circuit is sufficient for 10 amps? I don't think anybody here does for sure. While an extra 33% juice may not smoke-check the wires....I'd go find a 7.5 amp and put the same size fuse back in it personally.

And it's been a while since I did the double-horn thing, but seem to recall that circuit or horns were backwardsly grounded or something I don't fully recall or understand when I did it. Regardless, I'd use the existing wire as a trigger wire and do the double horns with a relay as describe here and other places.

 

[RossKean]

I have the PIAA sport horns on my 2011 with the stock fuse and no relay. Their draw is comparable to OEM and I haven't blown any fuses.
Going up in fuse size isn't usually a good idea. It is there to protect the wiring. For something with an intermittent draw like a horn and the fact that MOST electrical engineers build in a fairly large safety margin, you would PROBABLY be OK - do ya feel lucky? That said, there is no difference to the circuit with a normal draw if you use a 7.5 or 10 amp fuse (or even a solid bar of copper) but the fuse comes into play when there is a fault with a device or you make a wrong connection. Once I knew I had the wiring straightened out, I might put in a 10A fuse until I had a chance to swap it back to what is right.

 

[MotoMike]

I installed dual PIAA horns in my 2007A four years ago. I used the stock fuse and no relay. I have not had any problems.

As for using a 10 amp fuse in place of a 7.5 amp fuse, I defer to RossKean on that issue.

 

[JQL]

Earlier FJRs came with two stock horns (my manual still shows two horn positions though only one has a horn fitted). Therefore, there are two "recesses" and mounting points on either side of the radiator to accommodate horns. Also, as the original specification was for two horns, the electrics have been appropriately sized.

That doesn't mean you can wire any horns directly into the system. They must not be high draw like the Denali Sound Bomb or Stebel Nautilus etc.

The Piaa 85114 Slim Line 112Db 400Hz and 500Hz Twin Tone Sports Horns draw a total of just under 5.5 amps (2.7 amps each) and are a suitable replacement without the need for a relay under normal use (the signalling system fuse is rated at 7.5 amps). The slim line horns fit into the original recesses either side of the radiator. Depending on where you buy them, you may need a jumper cable to connect the two horns together so make sure there is one in the kit.

As an aside. There are a number of fuses (6) on the FJR rated at 7.5 amps so it's a good idea to have at least one replacement. There should be a spare already on the bike.

 

[graytaz]

The other aspect to this that no one else has mentioned is that intermittent heavier current draws like that for the horns will take a toll on the horn switch itself. Putting in a relay eliminates the impact on the horn switch and pretty much eliminates the likelihood that you hit the horn button some time in the future and it welds itself on and you have to go hunting for the horn connections to shut off the noise. Of course that will happen just when some a$$hole has just cut you off and your horns go solid on in reply and this a$$hole happens to be a short tempered large a$$hole and you can see where it goes from there. Relays are cheap insurance. JMHO.

 

[Buffaloears]

Thanks to everyone who replied....as a new FJR owner I really appreciate the support of the FJR communiity. I did install the horns this afternoon and they work great! I've owned triumphs and Harleys in the past and why they always install the cheapest horn on the motorcycle is beyond me, since it's undoubtedly the cheapest item on the motorcycle. Anyway, thanks guys.

 

[GOFFjr1300]

Do you know the size of the wire on that circuit is sufficient for 10 amps? I don't think anybody here does for sure. While an extra 33% juice may not smoke-check the wires....I'd go find a 7.5 amp and put the same size fuse back in it personally.

And it's been a while since I did the double-horn thing, but seem to recall that circuit or horns were backwardsly grounded or something I don't fully recall or understand when I did it. Regardless, I'd use the existing wire as a trigger wire and do the double horns with a relay as describe here and other places

Do you know the size of the wire on that circuit is sufficient for 10 amps? I don't think anybody here does for sure. While an extra 33% juice may not smoke-check the wires....I'd go find a 7.5 amp and put the same size fuse back in it personally.

And it's been a while since I did the double-horn thing, but seem to recall that circuit or horns were backwardsly grounded or something I don't fully recall or understand when I did it. Regardless, I'd use the existing wire as a trigger wire and do the double horns with a relay as describe here and other places.

That's the way of doing it. Relay and with the correct fuse. Watt = Amp *Volt. Use cable in connection to that formula.