How Could I Run A Wire...?

[muffler82]

Hello!

I should run a wire from the engine bay to the inside of the car, as I'd like to fit an extra switch to drive a... "more powerful" horn.

I've took a look on the bulkhead, I was used to my old Mini that had a lot of rubber grommets on it - if you had to pass a wire through, you only needed to choose one :) but on the Aygo as you surely know it's a lot different. I've seen a big grommet (something like 2") over there where all wires seem to run through. And 2 little ones, one for each side of the engine bay, but they look like some plugs instead of simple grommets.

I've read that someone ran a cable through the heater pipes' grommet, but I'd like to avoid as it's better to keep apart cables' plastic insulation and heat.

Another option that came to my mind was to run it along the bonnet releaser's cable, but it seems that the panel between door and bonnet (the one with the side direction indicator) has to be removed to gain sufficient access to work.

Does anyone have further suggestions?

Cheers!

Simone

[gordonh]

Could you not just use the existing wiring to the existing horn to switch a relay under the bonnet to switch on the more powerful horn?

This way you stay with only low power leads in the passenger area and you use the existing horn switch instead of having to add a new one. It will also make it a lot easier to return to spec when you sell the car (or get stopped for the musical airhorn that you added).

In case you aren't sure about relays, a couple of links:

http://freespace.virgin.net/tommy.sandham/relays.htm

http://www.mp3car.com/vbulletin/faq-empori...ow-wire-up.html

[Jan van de Wouw]

There's a large grommet for the main harness, I think that's the one you mentioned as it looks

about 2". In this grommet there's a provision for running extra wires, like for foglamps.

I ran my wiring for outsidetemperature and my airhorn through there without any real problems.

Have a look at the AIM for mounting foglamps, this has illustrated instructions...

[muffler82]

:D No, no musical airhorns - ok I live in Italy, but I'm not so cocky ;) I'm going to fit a pair of electromagnetic Motrax "Hootaz" instead.

The main reason I wanted to install an additional switch to drive those horns was to avoid any possible failure at MOT.

Sure I'll install a relay, if I'll find a way to fit the second switch I'll put a fuse also on the switching circuit (there's absolutely no need as usually relays draw something like 0.5A but it's better being on the safe side).

Sorry Jan, what's AIM?

(Does anyone know how much current the standard horn draws?)

Simone

[Jan van de Wouw]

AIM stands for Accessory Installation Manual.

Here's the one you need for the Fog Lamps.

CLICK (PDF)

Page 9 shows the wiring going through the Grommet.

I have my Airhorn (the BIG truck-kind) wired up through a relay that's selectable with

a small switch I've hidden underneath the steering column, by the height-adjuster-lever.

So the switch determines which horn sounds when I press the Steering Wheel Cushion.

The original horn is wired up to the positive side of the Battery through a fuse and the

cushion switches to ground, so I gave my relay positive too and ran the negative side

of its coil inside to the switch. I then cut the wire under the steering wheel and put the

switch in between: the center contact goes to the hub, one side to the original wire,

the other side connects to the relay. The relay switches positive to the airhorns compressor.

That way you don't have to fiddle with high-current wiring and can use a smaller gauge wire...

Here's a collage of my installation:

The switch is aberely visible, in front of (above) the lever, just as I wanted...

[muffler82]

Great work Jan!

And thanks a lot for helping. I had these on my Mini (although mine were red, not chromed, but the notes' frequencies were the same). No musical or alternate sound but a very audible PWAAAAH :)

I installed a second switch that drove the compressor via a relay. 2 fuses installed. I still have those compressor & trumpets, I liked to install those on the Aygo at the beginning but I feared that the 15A drawn by the compressor could affect the alternator, so I bought the Hootaz. (Later I discovered that Aygo's alternator gives a current output that's 5A higher than the Mini's one... ooops)

I'll let you know. Cheers!

Simone

[Jan van de Wouw]

My Airhorn isn't musical either, the horns actually sit on ONE base, with only one hose.

The Compressor is fused at 20A with 8 or 9 Gauge wire straight to the Battery and relay

even for the ground, but the headlights still dim a little bit when I use it, even when driving.

I only used one fuse for both relay and horns.

I usually have the airhorns selected and only switch over to the beepy

thingie when I lend someone my car or when it goes in for service...

[muffler82]

In the meanwhile I've tried to reach the grommet to cut the hole, but I can't even do with my hand only, let's imagine with hand + pair of scissors! :(

I'll try to find a way to. Eventual suggestions are clearly appreciated! :)

Cheers

Simone

[Jan van de Wouw]

I actually didn't cut it; I stuck a piece of metal wire trhough from

the inside, then taped the wiring to that and pulled it back inside.

[muffler82]

Great Jan! You're right! I run to try immediately.

Remind me I've to ship you a flask of Chianti wine ;)

Cheers!

Simone

[Jan van de Wouw]

I don't drink Alcohol, so that saves you a few £££ :D

Allways glad to help!

[muffler82]

:)

A bomb?... No, it's the circuit I've made to control the horns :)

Could you please tell me which is the horn wire's colour in the steering column Shell? As I've looked for it among the electric schemes I have, but the only reference I've found for the horn is its fuse rating :(

Cheers

Simone

[Jan van de Wouw]

There's a spiral cable behind the steering wheel with 3 wires in it.

The Airbag uses two cables on a Yellow plug, leave that alone,

the only remaining wire is white and lives inside a black plug on

itsself, even though there is room for more wires in the plug.

[muffler82]

Great Jan! Thanks again!

I've made the power side of the circuit with the good ol' N07V-K 1.5 square mms, the one we use here in Italy to make electrical systems in buildings. It's rated at 15A in standard conditions, it should be enough ;) I'll keep you updated.

Cheers!

Simone

[muffler82]

So I've installed the horns, here's a pic.

Haven't tried them yet, I'll let you know.

Cheers!

Simone

[Jan van de Wouw]

Great placement :P

[muffler82]

Thanks! :) hehe.

In the meanwhile I've tried, but their sound seems a little bit... "choked". Most probably because that area is quite totally closed and the sound escapes out badly. (I felt the car's floor vibrating while using :D)

As soon as I've got some spare time I'll try by moving them in a freer place, if possible. I'll let you know.

Cheers!

Simone

[muffler82]

Update. I've moved the horns to a freer place - on the other side of the car. Now they sing as they should do :)

Again, thanks for helping. Cheers!

Simone