Horn installer in VIC

[Skrallex]

It's really not that difficult. I do electrical design for DC systems daily as my job.

Look at the maximum current requirements of ALL the horns you want to install. Look at the stock fuse for the stock wiring harness. If it's 5/10/15A (and maybe check the owners manual to make sure it hasn't been replaced with an incorrect fuse at some point), then that means the existing (stock) harness is going to be okay up to that current without any issues.

Then, if you are splitting the harness at the horn, such as to install 2x horns on the same harness, make sure the current requirement of the 2x horns is less than the fuse (and thus the harness). Fuses are placed up-stream to protect devices AND cables down-stream.

Now, if your new horns require more current than this (such as air horns), then YES, you should be looking into another solution.

Also keep in mind that fuses and cables don't melt or burn immediately. They will take a sustained current of a certain value for a certain time before they heat up beyond what the insulation is rated for. Typically horns aren't used in a sustained fashion, so keep that in mind if you are sizing up a new harness. No need to go 10 gauge wire, etc. unless you really really need it.

As for relays, if you are putting one in, make sure you choose an appropriate relay. You can always check the coil resistance to determine what the coil current will be (which is the low-power side of the relay) for a certain voltage. ie. 130 Ohm coil resistance at 12V is going to require about 100mA to hold the relay closed.

[bumblebee]

As long as it doesn't need more power, like an air horn then the stock wiring does have a fuse so if it overloads it should blow the fuse first right?

OEM wiring harnesses are good for running OEM items

That's it

End of story

The air horns I linked do can and do draw more then 20amps.
And before everyone chimes in and says put bigger fuses in . No. Do not do that ever. Ever. Under any circumstances.

You never ever ever run any thing that's NON OEM like a horn with out a wiring harness and relay and fuse.

If you can't do a trade in electronics like I did over 20 years ago at least go to a TAFE and spend some time & $ educating yourself on electronics and how it works.

Or

Feel free to talk to a decent auto electrician who will tell you what I just said.

I'm done with this thread
It's your car
It's your money
Destroy it if you wish
But don't tell people to do stuff too it that you have zero clue about

[Lancer1993]

I agree any airhorn will need a rely and fuse, I was talking lessor horns like the ones I got which are still working fine after almost 4 years installed. It all depends on the wiring requirements. So yes I agree check the specs and if in doubt talk to an auto electrician.

[bumblebee]

I agree any airhorn will need a rely and fuse, I was talking lessor horns like the ones I got which are still working fine after almost 4 years installed. It all depends on the wiring requirements. So yes I agree check the specs and if in doubt talk to an auto electrician.

I understand full well what your saying
And I still absolutely 100% totally disagree with you
OEM stock wiring is for OEM products only
That's it
End of story
And yes wiring cam absolutely 109% burst in to flames and melt and cause all kinds of destruction in the blink of an eye
I know this cos I have seen it first hand
And I will always 100% stand by what I said in the fact that if you want to run anything other then a OEM horn you must run a wiring harness like the ones sold with the stebel horns I mentioned.

At the end of the day it's your car
And your money
What ever
But if you have any idea WTF your doing you will run a wiring harness.
Feel free to drop by your local TAFE and spend some time studying the fine art of electronics some day. You might just learn something

[bumblebee]

Something I think I may have forgotten.ro add

If you wish to run a air horn you MUST keep the OEM piezo electronic horn

If you keep the piezo electronic horn you absolutely 100% can run an air horn with it

However

If you run an air horn on its own with NO piezeo electronic horn you are absolutely 100% breaking the law

The simple reason is
Law Australian wide required that the instant the horn is.pressed the horn must work
This will never happen with an air horn
Few reasons why
First off there is a delay as the relay kicks in
Second is the delay as the pump gets up to speed.

Yes you can run an air horn like the ones I listed on this thread on a motorcycle if you wish however the same applies you must keep the stock OEM piezoelectric horn

I hate auto correct