Car Alarm goes off for no reason

new_girl

For some strange reason Oh car alarm goes off when it is parked outside the house,live in a quiet street so not much traffic going past, sometimes happens daytime others nighttime
Any ideas why

Inner_Zone

new_girl wrote: »

For some strange reason Oh car alarm goes off when it is parked outside the house,live in a quiet street so not much traffic going past, sometimes happens daytime others nighttime
Any ideas why

Make and model would help.

bryanb

Could be insects/spiders.

lovinituk

Its likely the internal battery in the alarm has nearly run out. As above, make and model will help with the answer.

ajb69

If it's only just started happening, maybe a spider inside the car dangling itself in front of a sensor? It's the right time of year, as it's mating season.

(I know these things as I am married to an arachnophobe...)

Other than that, battery might be on its way out, or door or bonnet switches. No doubt other things could go wrong as well. Some alarms have a test mode which will let you check out the switches.

Try disabling the interior sensors and see if it still keeps happening. Or close the air vents and put the heating on max, that'll kill any spiders in the car.

Drew

shaun_from_Africa

There are quite a few things that could cause this.

A faulty door/bonnet/boot switch or a damaged wire to one of the switches.
A faulty internal sensor (pressure sensor, impact sensor, tilt switch etc)
An insect inside one of the sensors.
Low battery voltage can sometimes cause problems.

What type of car is it and is the alarm a factory fit or an aftermarket one?

JustinR1979

Bonnet is often a favourite, especially on cars that only secure in the centre, tend to wobble a little in the wind.
Easy enough to disconnect and see how it goes.
I removed mine when it played up.

new_girl

new_girl wrote: »

For some strange reason Oh car alarm goes off when it is parked outside the house,live in a quiet street so not much traffic going past, sometimes happens daytime others nighttime
Any ideas why

Thanks for replies so far ,make is a Skoda Superb and has factory fitted alarm

BeenThroughItAll

new_girl wrote: »

Thanks for replies so far ,make is a Skoda Superb

If it's a 3U Superb (2001-2008) there's a good possibility there may be other issues as well if you look closely - like interior lights not working and possibly other electrical problems.


Head on over to www.briskoda.net and take a look on there for information on Superb water ingress. Lots to read.


If it's not a 3U, then if could be any of the things suggested already.

lovinituk

The alarm siren has its own internal battery that means the alarm will still sound even if someone tries to disable it by disconnecting the main car battery.

http://www.briskoda.net/forums/topic/126715-superb-alarm-info/

I had this with a Vauxhall Zafira. As the internal battery started to die the alarm would go off randomly until one middle of the night it wouldn't stop. I ended up just removing the siren completely. The alarm still sounds the car horn which is sufficient for me.

If you are not very hands on with a car, get it somewhere that can sort it for you.

Strider590

I won't be too surprised if the car battery gives up in the next few weeks.

Very common cause of late random alarms is the battery voltage dropping after the car has been parked up for a while, it gets worse at night when it's cooler.
Also the alarms internal battery may have gone kaput, this will be a small rechargeable NI-MH battery pack.
When the alarm detects a voltage drop on either battery, it will go nuts.

If you want to stop the alarm going off when the car is locked, you may have to open a rear door, knock down the lock pin on the drivers door and then shut the rear door again. This should lock the car without turning on the alarm.

lovinituk wrote: »

y started to die the alarm would go off randomly until one middle of the night it wouldn't stop. I ended up just removing the siren completely. The alarm still sounds the car horn which is sufficient for me.

If you are not very hands on with a car, get it somewhere that can sort it for you.

I cracked open the alarm siren on my Vectra and wired in a 4 pack of cheap AAA NI-MH batteries (<£5). This was cheaper than buying a new sealed battery pack and give the alarm 3x more backup juice (equating to around 45mins).

Allowing the car horn to be used instead of the siren is risky, because if the alarm does get set off, it'll drain the car battery in no time at all. If that happens over night, then it'll be a new battery job.

Also and perhaps worse........ If you had a fault accident and they found your alarm was disconnected, you might find yourself on your own with cancelled insurance, a car to fix, a 3rd party car to pay for, injury compensations and a nice fat fine in the post from the DVLA for having tax with no insurance.
The alarm and immobiliser are conditions of your insurance policy.