Alarm playing up flattening battery

[Brummmie]

Hi Guys, car runs drives unlocks/locks as it should, (Siren has never worked) but its just developed a fault where the alarm keeps clicking, (from under the arch where the siren is situated) it now flattens the battery overnight (in the Unit).
Like i say functions as it always has, just clicks and flattens the battery.

Any ideas??

[MKnight702]

Could it be the other way round? Dying battery causing the alarm to trigger the broken siren?

[Brummmie]

I dont think so, battery is really lively if i disconnect the battery it keeps its charge.
Also fairly new.

I tried disconnecting the battery to reset the alarm also, but its still clicking away.
Just gone outside and its gone quiet, but itll be back...

[Jhonno]

Have you measured current drain?