Fitting louder air horn

[collins_dan]

I go by the theory, the smaller the car, the louder the horn needs to be. My S4 has a single air horn that is working inconsistently, I suspect the compressor is giving up. I bought a "super loud" air horn and tried to just swap out the connections (purple=positive, purple/black=negative), but it sounded like someone stepped on a duck. I tested it direct to the battery and it worked fine. It's 12V 40amp. I would think the traditional wiring would be fine for that, but perhaps not. Thanks. Dan S4 SE Federal

[bcmc33]

Dan,

I would connect the horn via a relay with a 14 gauge cable direct to the fuse box.

[collins_dan]

I was thinking of doing that. Does it matter which fuse I come off? Seemed to be a number of open spades. Thanks. Dan

[Elanintheforest]

Dan, don't mess about...fit one of these.

Make sure you press the sound button on the advert

http://cgi.ebay.com/ebaymotors/MEGA-TRI ... C72%3A1171

Mark

[RotoFlexible]

The horn push and contact "pencil" are barely able to switch a relay, never mind a big load like a twin air horn that draws 40 amps (that's 480 watts @ 12 volts). A relay is essential. I don't recall the rating of the two fuses in the normal fuse box but I don't think they can handle 40 amps (in addition to their other loads). The contacts in the box tend to corrode over time, further reducing the ability to pass current (you're just heating the connections).

I fitted two "Highway Blaster" horns - not air horns, but similar in appearance and operation to the original Lucas or Clear Hooters units. They are fed through a dedicated fuse and a relay in a new panel I built and concealed under the dash. The fuse is a modern blade type. The horn is plenty loud.

[bcmc33]

Dan,

Make the connection to the ignition side of the fusebox. i.e. the side that is live when the ignition is switched on.

Andrew is correct in saying that 40A is at the limit for the standard 35A fuse, but unless you are in the habit of making long hoots on the horn, you should be OK.

As Andrew also said, the weak link is at the horn button end of the system - you would be best advised to take a good at this. I did, and it now mine works every second push.look

[SADLOTUS]

I fitted a pair from Halfords - the smaller compresser type (there's a large, small and integrated compresser type) easy fit with new relay and lovely loud.

My squeeky horns run off the central hooter push button, the air horns are activated by a converted GT6 overdrive switch by the indicator stalk.

...converted from toggle to 'push to make'.

[oldelanman]

Hi Dan,
It's also worth making sure you have good earth connections across the steering column u/j and from the rack to the frame, these do tend to get overlooked. I also found that the air horns themselves do not work unless correctly adjusted. Try screwing the trumpet in or out slightly - it seems that the gap to the metal diaphragm is critical - worked a treat with mine and I thought my compressor was the problem.
Regards,

[Frank Howard]

Make the connection to the ignition side of the fusebox. i.e. the side that is live when the ignition is switched on.

I would make the connection through the other side of the fuse box; i.e. the side that is live all the time. That's how most manufactures including Lotus does it.

[collins_dan]

I know this will sound stupid, but which side is the live side? The left side (white wires connected) or the right side (purple... connected)? Thanks. Dan

PS. All other connections have been recently refreshed. Does anyone know what the load of the original air horn is? I don't really want to overload the electrical system, I just want something louder than a squeak.

[collins_dan]

Those Fiamm Freeway Blasters are only 5 amps each.

http://www.fiammamerica.com/Product.asp?ProductID=156#

That seems like it might make a lot more sense. I could start with one and add a relay and another horn if needed.

Dan

[65 Lotus]

I tried two Fiamm Freeway Blasters. They both died a miserable, lingering death after a couple of months.

Ended up with one of these which I've been happy with now for a couple of years. Definitely use a relay.

http://www.wolo-mfg.com/air.htm

[collins_dan]

Scott, These are very similar to the one I bought. The issue that I'm hearing from the group is that it is 12 volts and 40 amps, which is a big demand on the wiring system. How did you wire yours? Do you know what your's draws? Dan

[RotoFlexible]

Those Fiamm Freeway Blasters are only 5 amps each.

http://www.fiammamerica.com/Product.asp?ProductID=156#

That seems like it might make a lot more sense. I could start with one and add a relay and another horn if needed.

Freeway Blasters - that's what I bought. I have a low and a high. They work fine 1-1/2 years after installation, but I don't use the horn much. Never tried them without a relay, because I did a complete wiring overhaul and added a number of fuses and relays at the same time I installed the horns. (I have relays for the horn, low and high beams, electric fuel pump, and heater blower.)

[alexblack13]

Hi All,
Also worth a look due to compactness and being bloody loud. Complete kit including relay etc.
Loads on ebay. Italian product I think made by a company called stebel or some thing like that. The model I used is called Nautilus due to design. The horn is very compact. Compressor and horns are all one unit. V neat. V V loud.
I can e mail (or post) a pic if you like.

Hope this is helpfull.

AB....