EXT: HELLA air horns

[pwrusr]

Horns on a car:
http://forums.nasioc.com/forums/show....php?p=8163344

the link to the horns that he has in his thread doesn't work, so here's the direct link:
http://www.griotsgarage.com/product/...rrivals&page=1

[xkjnboix]

I know this is a old ass thread but for those wishing to install hella supertone horns on a ground switched car its best to run a separate inline 20A fuse and relay harness.

The way our CB7's are set up, the horns are fed a weak ground lead which triggers the horn since the brake lights and horn are always powered with or without the engine being on.

The proper way to set up the CB7 with aftermarket horns is to take each horn and ground the negative contact where ever you choose to mount the horn.

Using a standard generic 20A 5 pin relay we will hook up wires as such:

87 =====> Positive contact on aftermarket horns
85 =====> Stock Negative OEM wire ( Blue / Red )
30 & 86 .=> Positive wire with inline fuse coming directly from Positive Battery Terminal. (you only need one wire and just "Y" them at the end to bridge 30&86)

NOTE:
87a => N/A, nothing, not used, so ignore it
The OEM Positive Horn wire ( White / yellow ) Just Tape it off. It will no longer be used !

By setting the CB7 up this way, we eliminate the brake light strain on the STOP HORN fuse and still maintain our OEM ground switch to the steering wheel.

[accordztech]

That is the better way to do it. Im just a lazy installer (been one for about 12 years now).

However if you have an issue with a weak ground, then adding a relay for the power isnt going to do squat. You still are restricted with a factory weak ground.

With this setup, you might as well do what you said but then hook up the Ground of the aftermarket horn to CHassis ground. Since essentially your changing the negitive signal the car gives to a positive with a relay. So when you hit the horn, it will trigger the relay to send good power from the battery, and at the same time the ground will be applied to the chassis at the horn itself.

[tommi]

i have the hella supertones on the 4dr and its loud as fuck. 118db using the supplied relay.

[xkjnboix]

That is the better way to do it. Im just a lazy installer (been one for about 12 years now).

However if you have an issue with a weak ground, then adding a relay for the power isnt going to do squat. You still are restricted with a factory weak ground.

With this setup, you might as well do what you said but then hook up the Ground of the aftermarket horn to CHassis ground. Since essentially your changing the negitive signal the car gives to a positive with a relay. So when you hit the horn, it will trigger the relay to send good power from the battery, and at the same time the ground will be applied to the chassis at the horn itself.

If you reread my post then thats exactly what I explained how to do ( i changed the color config on my post around for clarity )

if you ground the horn on the oem set up without the conversion relay then your horn will constantly go off since its ground switched. The only other possible way to do it is by converting the switch polarity via relay.

[accordztech]

Call me ignorant but I really dont see it lol.

Yes grounding the horn will make it go off at all times, however I just said ground one side of the horn WITH THE RELAY setup.

The relay setup is only active when the horn is pressed and it goes via pin 85 on the relay. So essentially without the horn depressed the relay doesnt allow any power from 30 to 87. Therefore no horn.

The weakpoint in your design is going to be the ground, like you said. So since it is now dependent on a relay, why not give it a proper ground as well?

[RyanD]

is there a good way i can get something like a train horn?

[accordztech]

is there a good way i can get something like a train horn?

Yeup. Those run with air and a resavor tank (a huge one). Just have to find a location for them and your set. But dont blow it in front of a cop lol.