just got a vec b cdx with the factory fitted alarm so thought il see if it all works, its works fine but its just the horn that sounds and not the power sounder, i know the power sounder works as i took it off from under the arch and it burst into life, when the alarm went off on my astra g both the horn and sounder went at the same time...does the vectra alarm work differently then? ie - the power sounder only activates if the car battery is dissconected ??

cheers