been having some trouble with the alarm on the C70.

car locks and unlocks as it should with the alarm remote and arms and disarms alarm also. the problem is irratic. the car can be alarmed for any period of time then all of a sudden the alarm will go off. it doesn't matter if i park the car facing the house or facing the street.car is at least 10ft from the road on the drive and my road is not busy sometimes it doesn't go off but then other times it could be 10mins and it goes off or sometimes hours. have sat and watched the cctv and nothing around the car at some points when it has gone off. i have removed air fresherener that was inside car hanging from the rear view mirror and checked all doors / boot / bonnet are closed as should be. even tried making sure all interor lights are switched off, stereo turned off and cd cassettes removed to make sure its not a power loss problem.

firstly car doesn't seem to have motion sensors inside it. does anyone have any ideas what may be causing this problem?

have tried disconnecting the nearside wires from the bonnet catch but with this done the alarm doesn't activate the dashboard led. so reconnected it.

is there a battery in the siren for back up at all that if its failing could cause the problem? or other trigger points?

any help be very much appreciated as its no doubt annoying my neighbours as sometimes its been small hours of the morning when it goes off and i do not want to leave the car with the alarm not set.