Beeping for minutes when parked

[James99]

Just wondering if anyone has an idea on this please? It's a 2003 W209 CLK320. I parked up as usual, got out and locked the doors. The car then started beeping - not the alarm siren but a beeping at 1 second intervals. Unlocking the doors, putting key in ignition, even starting the engine did not stop it. Opening the boot and closing it did stop it momentarily, but when I locked the doors again the beeping began again. After 5 minutes, the beeping stopped by itself. There is no message/malfunction indicated on the dashboard that I can see.

In case it is related, for the past 2 weeks the alarm has been going off at random shortly after parking up. This is the first time I've heard beeping like this though.

Many thanks for any help or ideas!

 

[andy@pcd-ltd]

I would say there is a chance that the alarm siren has got water in it. It is a very common problem on these cars

 

[James99]

Thanks for that. Think you may well be right - the alarm has just gone off randomly and this time it's more of a gargling siren noise. Can someone please say how to access the siren? Thank you!

 

[andy@pcd-ltd]

It is usually located in the nearside front wheel arch at the back behind the wheel

 

[James99]

Thanks again. So the wheel needs to come off and the wheel arch lining removed to get to it I guess.

 

[andy@pcd-ltd]

I will look on my star machine in a minute just to confirm

 

[James99]

Really kind, thank you!

 

[television]

Yes that is correct the liner has to come out,,and I think the siren as well,,you could unplug it for now

 

[James99]

Many thanks Malcolm! Just had Britannia Rescue out - alarm been going off most the evening now and thought they could do it rather than me with my inexperience and in the dark. Of course by the time they arrived the siren doesn't go off at all anymore, just the indicators flash when the alarm is triggered. Hoping it stays that way till I can get it sorted!

 

[television]

If it gets to the stage where it upsets the locking,, then it will have to come out

 

[James99]

Thank you for that further information, Malcolm. I've got it in for other repairs in a week's time so hope it will last till then.

Looking at the front right wheel arch liner, there are 2 fasteners missing from the front section so it flaps a little. Could it be that wheel arch that the siren is housed in? I'm wondering if water may have got in because of it (my last drive before it really played up was in quite heavy rain). I'm also wondering if my most recent wash I gave it a couple of weeks ago, where I also hosed down the inside of the wheel arches was such a good idea...

 

[television]

The Siren is housed in the rear section right at the top, they have batteries in them,, these can leak and like all rechargeable batteries they go short circuit when past their sell by date,,water can also cause the problems, they have been on back order this year

 

[James99]

Great photos, thank you! I'll get it checked out.

 

[James99]

Just to let you know, I got someone to remove the siren - as said here it was behind the wheel arch liner of the nearside front wheel. Many thanks for that as it prevented a long hunt! I'm amazed how low to the ground it is positioned. It just seems unnecessarily vulnerable to water there. The bracket holding it in place is covered in rust.

The siren itself (black round plastic box) has no obvious sign of damage and I can't hear water swilling around inside it, but I will open it when I have a moment. It looks sealed so not sure if it will open without breaking. But at least the siren is off and the car seems to be behaving correctly, touch wood.

 

[television]

Then just batteries expired James

 

[James99]

Ah that would be nice! It will be interesting to look inside. Is there a best way to open these? It looks like it is in two parts and can be prised open with a screwdriver but don't want to break it.

 

[television]

You go round the seam with a junior hack saw,, buy some new batteries if the PCB is not too bad glue back together using plumbers pipe solvent, and leave under pressure for 2 days, re fit to the car and smile as you have just earnt £80 with no labour cost either

 

[James99]

Great stuff thank you!!

 

[gh3382]

are the batteries a dealer part or can they be sourced elswhere.

gh3382

 

[Triv]

Maplin maybe, battery supplier more likely.
Many of these batteries (they are different in each model of siren I believe) are no longer available. However, the same battery may be found as a back-up battery in combi boilers.
Once you've dismantled your siren (a Stanley knife does it without damaging anything) and can see the code printed on the battery, I can make up a battery for you if one can't be found elsewhere.