Contour Enthusiasts Group Archives
Posted By: Mystique97 Any electrical gurus in the house? - 08/30/06 02:26 AM
I bought a dual air horn and want to hook it up separate from my factory horn how would I go about doing this? Should I just need wiring and a place for ground (chasis) and connect a wire to the fuse or relay under the hood for my factory horn and run a button for it?
Thanks in advance.
I still haven't quite figured out how horns work, every time I apply +12V to them with the body grounded, they just pop like if you do the same to a speaker. I remember one specific event when I had this weird looking horn that when hooked to the battery of my Pontiac 6000 wagon, it would POP and that was it. When I plugged the wire that goes to the OEM horn, it would honk (but sounded like crap, so I threw it away).

I'm thinking you will also need a horn relay, and that might be what makes the horn actually honk?

The Mercedes I had for a couple hours had an interesting factory setup. 4 horns, 2 "beep beep" style (like what a Honda has) and 2 normal (but really really deep) horns. There was a switch on the dash that would swap between the 2 sets.

Oh wait, you said air horns... AFAIK, you will just need +12V to the motor or valve for these to work. Just get some hot to a momentary contact switch, then from the switch to the horn. Good to go!
Posted By: Mystique97 Re: Any electrical gurus in the house? - 08/30/06 02:45 AM
Ya my horn setup has the relay with it so thats covered, and the directions say hook a switch up to it to toggle the 2. Looks gibberish to me.
Posted By: KerryKool Re: Any electrical gurus in the house? - 08/30/06 04:29 AM
Could you use the existing horn wiring on the OEM horm and route it to your other horn(s)?

Unless they want some other wire you don't have.
Posted By: Mystique97 Re: Any electrical gurus in the house? - 08/30/06 08:48 PM
Are you saying I splice into the factory horn wires? I don't want to splice into wires, I want to hook it up separate from that horn.
Originally posted by Mystique97:
Are you saying I splice into the factory horn wires? I don't want to splice into wires, I want to hook it up separate from that horn.




Then don't pay attention to the instructions saying to install a switch to choose between the two. You'd have to splice into the existing wire at this point.

What you will need to do for you to have 2 seperate horns that, if you feel the need, can both honk simultaneously by pressing both switches (with the factory one operating via the steering wheel pad, air horns via a seperate switch) is to find a source of +12V (could run from the battery, fuse block, or find one under the dash yourself) and hook that into the switch.

After that, run a wire from the switch to the horn. Then run a ground wire from the horn to the chassis, if necessary (most of the horns will self ground thru the mount when you attach it to the car).

Your horn will work after this.
Posted By: Mystique97 Re: Any electrical gurus in the house? - 08/31/06 01:44 AM
Well I already do have a +12V wire stripped covered in electical tape that prevously had a keyless entry installed on it. So your sayin all I need to do is wire it to the +12V wire under the dash and ground it? Sounds easy enough.
Just remembered. Think I'll need the relay still?
Originally posted by Mystique97:
Think I'll need the relay still?




Depends on how much amps the horn pulls. If it pulls a lot of amps, then you might need to use it.

If that is the case, then you would hook the switch up as said, but run the switched wire to the relay instead of the horn. Then you would hook +12V up to the input of the relay, then hook a wire from the horn to the NO (normally open) contact on the relay.

Note, the supplied relay may not even have this, but if you hook to the NC (normally closed) contact, the horn will sound all the time until you push the switch...

Reason they use a relay is so you don't run high amps thru a tiny switch (i.e. headlights).
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