My air horn draws too much current

[TheRiddler]

I installed a little 140db air horn on my bike a few months ago. It has a built-in compressor and it's way louder than stock. Because the wiring is identical, I just unplugged my old horn and plugged in the new one.

The problem is that upon pressing my horn button, all my lights dim as that horn's compressor draws so much current. Headlights, gauges, everything.

What do I need to wire up to fix this?

 

[nine_inch_rear]

Youll need to wire in a relay. You can use an "ice cube" relay-since they look like an ice cube. Buy them at any auto parts store.The hot lead to the relay will need to be fused, comming off the battery. The relay trigger can be from the horn switch.

 

[Crjunkee]

relay

http://www.ado13.com/techs/relay.htm

http://www.autozone.com/autozone/ac...sal-relay/_/N-2659?itemIdentifier=203873_0_0_

http://www.frys.com/product/4191633?site=sr:SEARCH:MAIN_RSLT_PG

 

[TheRiddler]

Thanks guys. Looks like the same thing I did to my heated grips, more or less.

 

[ST Guy]

Yep. Motorcycle wiring is known for being only barely adequate and the same is true for the horn itself and any wiring serving it. Remember to put the fuse for the line that supplies the current to the horn as close to the battery as possible. And the simple thing to do is to mount the relay somewhere close enough to the stock wiring for the horn and instead of plugging those connectors onto the horn, just plug them onto the #85 and #86 tabs on the relay. (If they fit.) Now you've got half of the circuit wired up. And it doesn't matter which wire goes on which tab. Here's my old hand drawn schematic:

 

[TheRiddler]

Yep. Motorcycle wiring is known for being only barely adequate and the same is true for the horn itself and any wiring serving it. Remember to put the fuse for the line that supplies the current to the horn as close to the battery as possible. And the simple thing to do is to mount the relay somewhere close enough to the stock wiring for the horn and instead of plugging those connectors onto the horn, just plug them onto the #85 and #86 tabs on the relay. (If they fit.) Now you've got half of the circuit wired up. And it doesn't matter which wire goes on which tab. Here's my old hand drawn schematic:

Your hand-drawn schematic is incredibly helpful

I also don't want to be anywhere near you when you press your horn button.

 

[ST Guy]

Your hand-drawn schematic is incredibly helpful

I also don't want to be anywhere near you when you press your horn button.

Not representive of my bike. I drew that for a friend. A single dual tone Nautilus is just fine, thank you.

 

[fast4d]

help me understand....

how will a relay prevent the lights from dimming?

the horn compressor will consume a certain amount of amps.

most relay I see are around 35amps?

 

[deathbug74]

help me understand....

how will a relay prevent the lights from dimming?

the horn compressor will consume a certain amount of amps.

most relay I see are around 35amps?

horn wiring often gets its power from the same wiring that lights the cluster, which can only carry so much current..if you divert most of it to power a big horn, the lights dim.

the relay provides an alternate feed for the power to the horn, all your horn button does then is tell the relay when to turn on.

the "35 amps" part for the relays refers to how much current draw they can support.

 

[Flying Pig]

My auxiliary fuse box even warned for me to not install a stebel or other air horn into the fuse box and stick it right on the battery saving the fuse box for other things like lights and heated elements.

Anyhow, I just did my stebel install two weeks ago. The box just came with the horn, one bolt/nut, and one fuse. No wiring since each application is different. There are companies like Eastern Beaver who sell a plug and play horn kit, but it's not all that hard to wire it yourself if you know enough about how to follow a schematic. If you get stumped, feel free to shoot me a message. I'm no expert, but I got mine wired up correctly the first time, no fuss

 

[ST Guy]

horn wiring often gets its power from the same wiring that lights the cluster, which can only carry so much current..if you divert most of it to power a big horn, the lights dim.

the relay provides an alternate feed for the power to the horn, all your horn button does then is tell the relay when to turn on.

the "35 amps" part for the relays refers to how much current draw they can support.

 

[nine_inch_rear]

help me understand....

how will a relay prevent the lights from dimming?

the horn compressor will consume a certain amount of amps.

most relay I see are around 35amps?

Relay carries the load, the horn switch just triggers the relay "on". 35amps is most commonly used, but you can go bigger. 35 is more than enough for a horn.

 

[VFRBenny]

Yep. Motorcycle wiring is known for being only barely adequate and the same is true for the horn itself and any wiring serving it. Remember to put the fuse for the line that supplies the current to the horn as close to the battery as possible. And the simple thing to do is to mount the relay somewhere close enough to the stock wiring for the horn and instead of plugging those connectors onto the horn, just plug them onto the #85 and #86 tabs on the relay. (If they fit.) Now you've got half of the circuit wired up. And it doesn't matter which wire goes on which tab. Here's my old hand drawn schematic:

Thats how I did mine.