Second Alarm Siren ??

[A3 T]

I'm thinking about adding a second siren to the factory alarm as the original one would be out performed by a casio watch....lol


Does anyone know of a positive or negative power source that is active when the alarm is activated?


I was thinking of taking a feed from the original siren but from what I've read it a pain in the a**s to get to (somewhere deep down under the sub) so would be handy if there is another one.


Any ideas ?

 

[TDIQ]

If you were to add a second siren then how would you wire it up so it goes off when the original one does? I'd have thought you'd need to tap into the OEM siren somewhere along the line.

I don't think it's too difficult to get to the original siren, the sub can be a pain to remove but not the worlds worst job.

 

[A3 T]

Isn't there any way to get to the wires before they go down behind the sub?

 

[a3tdi2001]

You don't need to remove the sub to get to the alarm siren. After moving the central locking pump out of the way you can get down to it.

 

[SiGainey]

Remove the rear light cluster and you can get to the siren from there. Access is a bit tight though!

 

[A3 T]

I took the panel off today and had a quick look....

Are any of these wires leading to the siren:




Also what's inside that foam block (marked 1)?

 

[fran-s3]

1 Is the central locking pump I believe!

 

[aragorn]

It depends which siern you have.

If its the older "honk" siern then its just a simple 12v feed that you can tap into.

If its the newer "beep" siren, then its not. The newer siren has electronic gubbins, and uses a signal from the ECU to control it.

 

[A3 T]

Mines the poxy beep beep one


Does that mean i wont find any + or – feed when the alarm is sounding?


I did think of tapping into the hazard light relay but then i thought....What happens when i use the hazard lights....lol


Unless... Is there a separate feed to the hazard light relay for the alarm?

If so i could use a diode and tap into that

 

[aragorn]

The "beep beep" siren has three wires, permanent live (to power the electronics and charge the battery), ground and "signal".

"signal" is an electronic bus that the alarm and siren use to talk to each other, its not just a simple "on" or "off" connection like the older cars. The alarm will simply send a "make noise" command to the siren and the siren will obey.#

Tapping the hazards might work.

 

[A3 T]

The "beep beep" siren has three wires, permanent live (to power the electronics and charge the battery), ground and "signal".

"signal" is an electronic bus that the alarm and siren use to talk to each other, its not just a simple "on" or "off" connection like the older cars. The alarm will simply send a "make noise" command to the siren and the siren will obey.#

Tapping the hazards might work.

Thanks mate


Is there a separate feed straight from the alarm to the hazard relay or does it get spliced into it somewhere hidden in the loom?


Also can you let me know where the hazard relay is as i cant find it on the net.....lol

 

[A3 T]

Hmmm....

It seems as thought the relay is built into the hazard switch (I've never seen that before) and has a load of wires going into the back of it.


Does anyone know if one of them wires is from the alarm?

 

[A3 T]

Does anyone know how i would find out what the pin-outs are the the hazard relay ?