I want to add a louder horn to my car to ensure motorists notice me in dangerous situations. I know there are lots of options out there from vendors such as Moss as well as cheapo units at Auto Zone etc.

I found a horn at Griots Garage that I may want to install. The Italian Air Horn is inexpensive, well made and loud. Ufortunately, unlike the Moss horn and others it does not gradually increase in volume, too bad. When you have a horn that blasts loud from the start its hard to give courtesy taps or beep hello.

This got me wondering if it is possible to split the two horn buttons between two different horns? Yes I realize this makes using the loudest horn chancy in an emergency, and you risk blasting the cute admirer waving on the sidewalk.

The other option is installing the loud horn as the default and wiring the factory horn to an aux switch for the gentler "hello" beeps.

I do like the thought of that classic Italian horn sound though. Thoughts?

 

why don't you just tap a toggle switch between your factory horn
and air horn compressor?

i use fiamm airhorns on my other cars. sounds great. :smile:

 

You could add a timer relay that would require a half a second of stock horn before the air horn kicks in. This would allow friendly beep-beep taps :smile: or a beep-BLAST as the situation required.

 

I am pondering this mod also...want to add a roadrunner type "beep beep" but don't want to sacrifice louder factory horn for safety. I like the simple toggle switch idea. Does anyone know what the wiring path is for the 2 factory horns? Do they converge somewhere in the bonnet or run independently to the steering wheel? Have you heard of anyone successfully tapping into the steering wheel buttons? I'll take a look myself later but just wondering if anyone's already scoped it out.

FYI, if you are considering an air horn in addition to factory, and want the delay effect instead of a full toggle, it might not be necessary to use a relay. I read in another thread that someone did this with no relay and still got a short delay because of the way air horns work - enough so that they could easily do a short, controlled beep of the factory horns only before triggering the air horn. The amount of delay probably depends on the air horn, though, so a relay would be the safer approach.

 

I talked to the folks at Griots and they said the horn makes a sound immediately. The relay idea is great, the description of the kit did mention a relay and instructions are included, perhaps they pertain to such an installation. I'll follow up with results.

 

I've posted this page to help out:
Vince's air horn install How-To

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VinceAndJessica.com

 

Thanks, Vince! :smile:

 

actually, air compressors need about 0.5sec to get enough air into the tubes
to actuate the horns. for example, if you have an alarm system that beeps
the horn to lock/unlock, that's not enough duration for the compressor to blow
enough air to the horns...it will click (relay) and make a funky psshh noise for
a split second.

i would just tap the wires for the toggle switch by the horn wire terminal at
the horns. this way you won't cut any wires so your warranty should not be
terminated.
if you want just a beep beep type of tone, you won't need both
hi/low freq horns.

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03 Cooper-S IndiBlue/Blk: #1 #2 #3, Leather w/ antherasite int, Factory aero kit, R90 w/ SP9000, Alpine 6CD MP3 changer, Autoclearguard, Laminx amber fog cover. Winter: SpeedEdition TK5 16x7 with Pirelli P6FS 205/50 // Modded 02WRX //Modded 01 G20.

 

>>i would just tap the wires for the toggle switch by the horn wire terminal at
>>the horns. this way you won't cut any wires so your warranty should not be
>>terminated.
>>if you want just a beep beep type of tone, you won't need both
>>hi/low freq horns.
>>

I think I will try for the toggle approach, where in one setting I can get the regular factory tone (both hi/low freq factory horns) and in the other setting I'll activate a single roadrunner "beep beep" horn (from JCWhitney). The problem with this is that I'd need to tap the toggle at both of the factory horn wire terminals, unless their wires converge somewhere else that is convenient to tap into. Any thoughts?

 

naw, no way around it unless you start cutting wires. you might be able to
tap it from the fuse box, but dealers hate it when you tap stuff from the
fuse box due to possible overload, etc.

just get a DPDT toggle switch and use good wirewraps to insulate the wires.

trigger wire to the 2 center terminals:

DPDT switch configuration:

Air horn O O (leave empty)

Trigger1 O O Trigger2

Factory1 O O Factory2

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03 Cooper-S IndiBlue/Blk: #1 #2 #3, Leather w/ antherasite int, Factory aero kit, R90 w/ SP9000, Alpine 6CD MP3 changer, Autoclearguard, Laminx amber fog cover. Winter: SpeedEdition TK5 16x7 with Pirelli P6FS 205/50 // Modded 02WRX //Modded 01 G20.

 

Hey, thanks kenchan! I think I get it now...but one more question: when you look at the factory horns, is it obvious which wire is the trigger wire? I.e., does the ground wire just attach to the chassis somewhere near the horn so it is clearly the ground wire and not the trigger or is there some other way to tell which is which?

 

hey no prob. :smile:

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03 Cooper-S IndiBlue/Blk: #1 #2 #3, Leather w/ antherasite int, Factory aero kit, R90 w/ SP9000, Alpine 6CD MP3 changer, Autoclearguard, Laminx amber fog cover. Winter: SpeedEdition TK5 16x7 with Pirelli P6FS 205/50 // Modded 02WRX //Modded 01 G20.

 

Sounds easy enough. Thanks again!

 

I appreciate all the valuable information.

If you take a look at the horn I ordered you will see (and read) that the compressor and horns are contained in the same housing. Two calls to Griots iquiring as to whether or not there is a delay yeilded the same results, there is no delay. I suspect that this is due to the close proximity of the compressor to the horn. Given that, I feel I may be left to replacing one (or both) of the factory horns with the Griot horn and wiring the factory horns to a new switch.

If this is my course, can I get some advice on how this might be done? Will the factory horns need a relay to wire them to an aux switch?

Thanks for your help.

 

kermini- if you use an additional replay to toggle between the factory horn and
compressor, you will need to send additional 12v power to the relay to latch/unlatch.
It would be easier just to use the DPDT toggle as you won't need to worry about
relay dying on ya, etc.

you will need to use the relay that comes with the kit to trigger the
compressor. the compressor must get direct 12v power from the battery
or a 30A handling fuse block. The compressors usually runs on a 20A fuse,
so you want the extra headroom.

_________________
03 Cooper-S IndiBlue/Blk: #1 #2 #3, Leather w/ antherasite int, Factory aero kit, R90 w/ SP9000, Alpine 6CD MP3 changer, Autoclearguard, Laminx amber fog cover. Winter: SpeedEdition TK5 16x7 with Pirelli P6FS 205/50 // Modded 02WRX //Modded 01 G20.

 

Actually I'm not interested in being able to toggle. I want to hook the air horn up to the buttons on the steering wheel and wire an aux button to the factory horns. The two would be totally independant of one another. How would that work. Wire a relay from the battery to the horn via a momentary contact button?

 

im not sure I understand wat you want to do cause by using the DPDT switch,
you still control either the airhorn or factory horn from your factory steering wheel
buttons..

how do you want to operate between the two horns? give me an example
and i think i can help you out. :smile:

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03 Cooper-S IndiBlue/Blk: #1 #2 #3, Leather w/ antherasite int, Factory aero kit, R90 w/ SP9000, Alpine 6CD MP3 changer, Autoclearguard, Laminx amber fog cover. Winter: SpeedEdition TK5 16x7 with Pirelli P6FS 205/50 // Modded 02WRX //Modded 01 G20.

 

If I may interject late in this conversation...

kenchan, are you saying that you can run a relay to one of the horn buttons on the wheel, and the other to the opposite button?

I'm about as inept as anyone at electrical work.... Z-Z-ZAP!

 

Lets say you wanted to replace the factory horns with the aftermarket one. So you disconnect the leads to the horns, terminate one dead. The other lead is attached to the new horn. So now the horn buttons on the wheel operate only the new horn, using the factory wiring. The factory horns then would be used only for "hello" taps of the horn. New wiring would be needed as well as a small button mounted on either the dash or between the seats, say in the console where the mirror controls are.

 

storer- nope. unless you do extensive rewiring and modification to your
steering wheel. on most factory steering wheels, both buttons only activate
one trigger line. the trigger is then split into 2 wires going to the individual
factory horns.

kermini- ok, yah you will need to get a momentary 12v switch for your 'hello'
factory horn. It will be wired completely outside the airhorn circuit. make sure
the momentary switch can handle the factory horn load (any automotive momentary
sw rated at 12v should be okay as i believe the factory horn is only like 3-5A.

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03 Cooper-S IndiBlue/Blk: #1 #2 #3, Leather w/ antherasite int, Factory aero kit, R90 w/ SP9000, Alpine 6CD MP3 changer, Autoclearguard, Laminx amber fog cover. Winter: SpeedEdition TK5 16x7 with Pirelli P6FS 205/50 // Modded 02WRX //Modded 01 G20.

 

But Kermini, couldn't you get that same functionality using the DPDT toggle approach? Here's how it would operate: you'd leave the toggle switched to "air horn" mode most of the time...when you push on the horn buttons on the wheel, the air horn blows. Then, when you want to do a friendly beep of the old factory horns, you first switch the toggle over to "factory" horn mode, then a push of the horn buttons on the wheel activates the factory horns. When done with the friendly beep, just throw the toggle back to air horn mode. I guess the only thing you couldn't do with this that you could with a completely separate momentary button is blow both sets of horns simultaneously, but not sure you'd ever want to do that.

 

>>But Kermini, couldn't you get that same functionality using the DPDT toggle approach? Here's how it would operate: you'd leave the toggle switched to "air horn" mode most of the time...when you push on the horn buttons on the wheel, the air horn blows. Then, when you want to do a friendly beep of the old factory horns, you first switch the toggle over to "factory" horn mode, then a push of the horn buttons on the wheel activates the factory horns. When done with the friendly beep, just throw the toggle back to air horn mode. I guess the only thing you couldn't do with this that you could with a completely separate momentary button is blow both sets of horns simultaneously, but not sure you'd ever want to do that.

The drawback I see to that is it takes two swithces and two switching motions to operate it. Perhaps you could wire DPDT that not only diverts the power to the "hello" horn, but also switches it on so it beeps.

 

>>The drawback I see to that is it takes two swithces and two switching motions to operate it. Perhaps you could wire DPDT that not only diverts the power to the "hello" horn, but also switches it on so it beeps.

I see what you mean. To get single motion operation of each set of horns, I think it would be best to wire a completely separate circuit.

 

For the two horn approach, Aston Martin commonly places a rocker switch on the dash, pushed in the standard horn blast, pulled out the air horn blasts. This switch is the relay, and the horn button functions the same, regardless of which set of horns is in operation.

 

you guys have the multi-function steering wheel? my left-hand middle switch doesn't seem to do anything... perhaps you can wire your 'hello' horn to that
sw.

but you may need to think of ways how to go about the coilharness under the
steering wheel hub. you probably dont want wires twisting inside the steering
wheel hub on a daily commuter.