Outside alarm box ont work

[HappyFace]

My house alam only sounds inside. im not sure if it is wired correctly or whether the outside siren and light need replacing. have you any ideas on how to wire it up (wiring diagram) or where i could get a compatible box? thanks

[buildersmate]

Although the generic connections will be similar between different manufacturers, descriptions of terminals are likely to be different. Generally there will be 2 power supply wires to drive the siren PCB control (controlling, for example, tamper protection on the external box) at 12v and 0v; 2 wires driving the siren itself, supplied from the internal control box; and (maybe) 2 wires to drive the strobe (if you have one), also driven off the internal control box. You seem to be saying the internals work OK, so the problem is with the external unit or its wiring. Some systems protect with a fuse in the siren driving circuit (the second pair of wires in my list above). This fuse (small - 20mm long typically) will be inside the control box inside. Look there first - it may be as simple as that. If you post what system you have, we may be able to provide you a weblink to circuit information.

[antiguru]

Has it ever been audible outside?

It may be that your system is set up like this deliberately. If you think about it, an alarm is to deter someone who is inside the house from staying or alert the occupier to an intruder. If the system is set to automatically call the police or a central hub, it doesn�t need to be audible outside. Neighbours complain about loud systems, and statistics I�ve seen show that neighbours are unlikely to approach a house with an alarm going off incase the intruder is still inside.

I recommend approaching the manufacturer of your system and asking them whether it should be heard outside or not before touching any wiring.

[fbg40]

Happy face
I think, in all probability, that your outside "siren" is a dummy box. Most alarm system providers just put up a dummy box to deter would be burglars. Unless it was working before of course !! In which case, contact the provider/manufacturer of the system.
Good luck
FBG40

[HappyFace]

buildermate - it was bought from Wickes about 7 years ago. No model number.
FBG40 - I have looked inside the box and it is all wired so its not a dummy box.