Funny things going on with the alarms/hazards

[SignumGB]

So, started last night and still happened today. Locked my car after getting home then the neighbour chapped on my door 20 mins later to say I left my hazards on. Thought strange.. didn't put my hazards on. Opened car, then locked it again. Within a few minutes hazards came back on again! Checked all doors were closed properly incase that was the issue. I did notice when hazards flashing, the alarm/immobiliser light on dash was flashing quicker than normal. Locked again... same thing! So went to bed with car unlocked as didnt want hazards coming back on and draining battery.

This morning went out to the shops. Came out and hazards flashing again! So by this point, yup there is something up with the alarm/immobiliser system.

Have any of you had this issue? Currently my car is parked on the drive unlocked so hazards won't come on.


Cheers

[seanc]

Could be the battery in the alarm siren failing? I think it's lucky the siren isn't going off too - there should be a way to lock it with the alarm off, perhaps with the key in the door - check the manual and then see if the hazards stop flashing.

[SignumGB]

Originally Posted by seanc

Could be the battery in the alarm siren failing? I think it's lucky the siren isn't going off too - there should be a way to lock it with the alarm off, perhaps with the key in the door - check the manual and then see if the hazards stop flashing.

Yeah that came up as a fault code in last service but it was something like £250 to replace the siren unit (internal battery inside). So gave it a miss then as was already forking out on discs, pads and trailing arms, plus it wasnt needed for a MOT pass either. I guess it's finally caught up with me.

[SignumGB]

Just an update.... It has stopped now.... Which is good as it will save me £250 at least for now over Xmas!

[Tatsfield]

Someone took the siren module apart and changed just the battery which saved him over £200 but the module is not designed to be disassembled so it's a fiddly job. See this YouTube video on breaking open the siren and replacing the battery. https://www.youtube.com/watch?v=Yu8TYyZ0PIM and a source of the battery on ebay https://www.ebay.com/itm/VARTA-Mempa...kAAOSwsfRc56cF

If the failed battery hasn't destroyed the PCB, the job isn't rocket science but breaking into the siren unit and opening the battery mounting will require a little finesse!

[apersson850]

You can't lock the car without the alarm getting active. But you can disable the interior movement sensor, in case that's triggering the alarm.

Like you would do if you have a dog in the car, for example. Or lock your kids in...

[SignumGB]

Originally Posted by Tatsfield

Someone took the siren module apart and changed just the battery which saved him over £200 but the module is not designed to be disassembled so it's a fiddly job. See this YouTube video on breaking open the siren and replacing the battery. https://www.youtube.com/watch?v=Yu8TYyZ0PIM and a source of the battery on ebay https://www.ebay.com/itm/VARTA-Mempa...kAAOSwsfRc56cF

If the failed battery hasn't destroyed the PCB, the job isn't rocket science but breaking into the siren unit and opening the battery mounting will require a little finesse!

Yes I came across that a while back after service but did seem a faff about. Might be a post xmas/New year job I get done at my Volvo garage.

Cheers

[Tatsfield]

I seriously doubt whether any Volvo garage will change the battery in the siren. They will only want to replace the entire unit. Quite rightly as the battery change is experimental work taking extra time to carry out with unknown parts quality and if it doesn't work they would not want to have to explain to you that they were having to replace the expensive siren at your expense on top of the charge for the failed work. If you have the DIY skills it's worth a go but if you haven't, having a garage change the siren will be the only way to go.

[SignumGB]

Originally Posted by Tatsfield

I seriously doubt whether any Volvo garage will change the battery in the siren. They will only want to replace the entire unit. Quite rightly as the battery change is experimental work taking extra time to carry out with unknown parts quality and if it doesn't work they would not want to have to explain to you that they were having to replace the expensive siren at your expense on top of the charge for the failed work. If you have the DIY skills it's worth a go but if you haven't, having a garage change the siren will be the only way to go.

Thats what I meant, I would get them to replace the unit, hence an after xmas job as its not a cheap part.

[JRL]

It really isn't a difficult job if you want to save a few quid though. Did it on mine about three years ago, hack sawed the unit apart and then used insulating tape to seal it up again. Hardest part was removing the security bolt holding it on. No problems since and a hell of a saving. Around a tenner for a new battery and about two hours of my time.