Aftermarket horn electrical issues

[slimx]

Hey i've tried multiple aftermarket horns and im getting the same issue everytime.
Once connected, i goto try the horn out and all i get is a click from the fusebox.
The only horn i manage to get to work was a HAIGH Musical Air Horn, which i do not want -.- it was just to test the stupid thing.

Im after a KLAXON i just love that sound
anyone got any ideas?
I have been to a couple auto electricians and well.. they dont have a clue. I asked some audio installers same with them. Some research on the net gave me no results maybe im just not seeing it..

My last option was to contact one of the horn manufacturers so i gave HAIGH a shout.
They said that maybe the fuse acts as a resistor too, and to ask someone who would know a little more about the cars electricals someone well associated with mx5's. They said maybe you can install an aftermarket fuse which appearantly is required for MERCEDES vehicles. But its $40! i dont wanna pay $40 to find out whether it works or not. lol (its gonna be coming from overseas so i cant really return it)

And yes i have tried multiple klaxon horns, one of them an ebay job and the other i bought from autobarn they had different packaging but they both did just write KLAXON HORN and OLD CAR HORN none of them had an actual BRAND but different packaging

So.. can anyone shed any lights on this? Sorry for the crap explanation.

and im well aware that i can wire it up seperately on to a switch of some sort. I want it to work from the original wiring and the original horn button though

[OurCognitiveSurplus]

Short the relevant fuse with a bit of wire and see what happens.

[Locutus]

Short the relevant fuse with a bit of wire and see what happens.

DO NOT DO THIS.

how much power does the horn draw? (in watts)
how much current is the fuse rated for? (in amps)

[Mr Morlock]

try the library for book on auto electrics . A suggestion is "How to Diagnose and repair automotive electrical systems". Author is Tracy Martin and you can buy it on line. Many have fitted air horns and standard horns to MX5's without problem- me included. You may also need a test light or multi meter. Any horn you buy should have a wiring diagram and you do not need to run a separate switch/ horn push to trigger the horn.

The other way to do it is simply go to an auto elect and ask them to fit a horn for you- they will know how to do it. Locutus is right in my book . If you ever have wiring catch on fire it is a scary thing.

[Sailor]

Good chance you'll need a relay to supply battery power direct to the horn.
Often wiring is either too old (black wire) or cannot handle the load.
Lancia owners know these things

[slimx]

Honestly these horns have no information what so ever on them. I cant seem to find a proper BRAND NAME klaxon horn.

A Relay might work. But where would i find the one i exactly need. JayCar probably but the service at Jay car in my area is just shocking they dont know anything themselves.

Wiring diagram is useless its just positive to positive and negative to negative its a straight forward process. I've installed many horns before never had an issue like this.

The thing is ive installed this into many of my friends cars, all honda's now that i think about it.
The only difference i can find between the honda's horn setup and the mazda's setup.
in the MX5's case it is a 1 wire setup so there is only a positive coming from the factory horn wiring harness so you have to earth it seperately, which obviously i tried but got no result.

I did take it to a local auto electrician and he just looked at the way i installed it and said "mate, I wouldnt have a clue it just doesnt seem to be drawing the power". I explain the problem and he just stared in my face. The other moron said he wouldnt have a clue how to install an aftermarket horn.

I went to mx5mania a while back to about this issue they didn't have a clue either they said that it normally just works but appearantly they only ever dealt with air horns and this is more of a electrical horn.

This is the current fuse..
its the stock one.
http://imageshack.us/photo/my-images/26 ... 01523.jpg/
judging by .. what it says on it, it must be a 10A but its a weird ass fuse!

[jorgan92]

Just go to Jacar/Autobarn/Supercheap and get a 20 amp (?) or maybe 40 amp relay and follow basic diagram below



worst case scenario you waste $5 and 20 minutes, best case it works.

as someone mentioned earlier alot of the time the wires can't handle the amps drawn by a new horn hence a relay is needed

[Locutus]

yes - the correct way to do this is with a relay.
the 'wierd ass fuse' you have in your pic is a relay. they come in different shapes and sizes.

if you spend 5 mins planning the wiring there is no reason why the horn won't work, provided it is a 12V model and it's not a dud. the hardest bit would be neatly tapping into a high current power source in the engine bay.

[Okibi]

+1 relay

[davekmoore]

The loud Nautilus horns come with a relay, although mine didn't need one even when wired along with the original horns.

[Zcootz]

I'de still put a relay in. Just because your setup works with the existing and aftermarket horns now doesn't mean it will continue to. The increased current draw will cause pitting in the contacts of the switch and it will probably fail later. Go the relay.