Alarm has started going off for no apparent reason

[gas guzzler]

As title, the alarm has started going off quite randomly. I stop it by disconnecting then re-connecting the battery and that seems to do the job for a while. Any ideas about solutions?

Cheers Andy

[BladeRunner919]

Probably the bonnet switch. Open the bonnet and you'll see the plunger on the slam panel. Just unplug it and see if the problem goes away.

[Robert T]

Which alarm do you have? The one with the separate fob or the one with the buttons on the key?

What happens if you just lock the car with the key and not the remote?

Cheers R.

[gas guzzler]

Cheers for replies, had forgotten about the under bonnet switch. I've got the buttons on the key but have not used the third button, I'll try things today. it's one very loud alarm so try to get it switched off quick.

Andy

[Koolflyer]

My 97 2.8 Roadster with separate remote started to alarm randomly. My battery was old and didn't hold its charge for very long, bought a new battery and quiet as a mouse....so far

[lightning]

Bizarrely the alarm on my 2002 3.0 has just started doing this as well!!
Can somebody tell me where the alarm unit is located (send me a PM....don't put it on here for public viewing!)

[gas guzzler]

Well it wasn't the bonnet switch, disconnected that earlier and it just went off again.

Think I'll just disconnect the alarm, cars kept in the garage most of the time anyway.

[Robert T]

Okay, with the separate fob alarm, there is the possibility of not being able to disarm the alarm with the remote and the only way to do it is a right fiddle. It is provided with a small key to turn of the siren for this reason.

With the alarm with the buttons on the key, even if the remote fails completely, you can disarm the alarm by putting the key in the ignition and turning it to position II. There is therefore no key to turn off the siren.

Locking the car with the key (rather than the remote) does not set the alarm. If the alarm still goes off, the culprit is likely to be the tilt sensor in bottom of the left-hand boot well, and it is likely that it has drowned. If the alarm behaves itself, then it could be the stereo anti-theft switch (wired in parallel with the bonnet switch) or the interior movement sensors. You can test for the latter by double-locking the car - lock with the remote and then press lock a second time within 10 seconds.

Cheers R.

[gas guzzler]

If the alarm still goes off, the culprit is likely to be the tilt sensor in bottom of the left-hand boot well, and it is likely that it has drowned.

Cheers R.

Now that would make sense, the boot got absolutley flooded the other weekend due to it being more or less open when there was a downpour, I will have a look there didn't know about that sensor. Have disconnected it for the time being as I really don't want to be working in the car when it goes off

Cheers Andy

Good call, just been into the garage to have a look the sensor was indeed drowning, have emptied the water out and will leave it a few days to dry out and see if it still works after that
Cheers