Car Alarm Activating

[NID]

Hi Just hoping that someone can help with a problem with my car, which is driving me and more than likely the neighbours mad. It is a 2002 A4 TDI SE, for some months the car alarm activates for no reason. Some months ago, we did notice water in the passengers side footwell, the drainage channels were unblocked and this has now dried. The alarm seems to go off when there is heavy rain, but I can not find any signs of water ingress. Any advice would be appreciated,

Many thanks

[JR001]

I have the same year of A4. It is normal for the siren battery to be dud at this point. I used to think it was activated by the rain, but it was acting up at other times. I got fed up with the problem and removed the siren and battery unit myself. It's dead easy, about half an hour total the first time you do it. It is more than likely your siren battery. £80 for the part and £70 to fit by dealer, but I would recommend saving yourself the £70. As long as you can use a hex socket and screwdriver you can do this job.

Worth getting it diagnosed by dealer or ind. specialist.
The siren unit is in boot well at the driver's side under the rear light cluster and you will have to remove some of the trim in the boot to get at it. It's fixed to a bracket that is attached to the car body but the new sirens come with a bolt about 2-3mm larger diam than the ones found in 2002 model so you will need an 8mm drill bit to make a hole in the bracket to accept the new siren, and a new 8mm hex nut and washer. It will be £80 well spent, it is such a relief when this problem is solved.

I have pics and instructions for the job if this will help. If you want then PM me with your email address and I will send them.

Cheers

[NID]

Thanks a million that woudl be great - I have PMd you my email.

Thanks again!

[jak]

If the water got into the convenience module which is situated under passenger side carpet it can cause the alarm to go off. I assume you haven't actually lifted the carpet to check.