Urgent - neighbour in distress

[ScottBacon]

Gents

My neighbour has literally just popped around with a problem on her 2003 C class coupe C180. The car is making a weird noise repeatedly every 5 seconds or so and this has been happening for approx 1 hour. It sounds like the alarm but could be fan or heater or something like that. The noise is coming from underneath the car immediately behind the near side front wheel, there is a cover on the underside but I can't get it off (or maybe that's don't want to cos I know nothing about cars). The best way I can describe the sound is like an insect sound that you'd get on holiday on the continent but multiplied by a factor of 10.

Any clues please ?? I need to go to bed soon

 

[brucemillar]

Probably the Alarm Klaxon has packed up. I believe that you have to remove the inner wheel arch trim to get at it and it can then be disconnected. You may want to try and disconnect the battery to see if that stops it.

 

[Neil Mackay]

Yep I'd say alarm siren too! Mine decided to pack up in the middle of the night! Sounded like a strangled cat! They have batteries soldered onto the boards that corrode and go bad! Think mine was about £130 odd quid to be replaced and coded by star! Not much you can do about the noise! The mechanics hid my old siren in the apprentices tool box.......

 

[ScottBacon]

Yep I'd say alarm siren too! Mine decided to pack up in the middle of the night! Sounded like a strangled cat! They have batteries soldered onto the boards that corrode and go bad! Think mine was about £130 odd quid to be replaced and coded by star! Not much you can do about the noise! The mechanics hid my old siren in the apprentices tool box.......

Thanks very much for the info

I think you are saying that the noise cannot be stopped right ?

 

[Neil Mackay]

Not unless you take the siren out, and bury it under loads of towels or sound absorbing material! Yep pain in the rear!!!

 

[brucemillar]

Thanks very much for the info

I think you are saying that the noise cannot be stopped right ?

If it has a separate back up battery then no it the noise will continue. You could try disconnecting the main battery in the hope that it is running from that.

Failing that move the car to somebody else's house for the night.

Good luck.

 

[KillerHERTZ]

Disconnect the battery for the timebeing, (or even remove it completely for security).

You will need to ideally remove the wheel to get to the wheel arch trim, then once thats off you will need a special hex key which has a hollow centre (you will see what I mean when the bolt is visible) - they are available in a set from Maplin etc

Its the internal battery which has failed on the alarm.

 

[ScottBacon]

Hey gents thanks to you all for your quick and accurate help.

I have disconnected the main battery and the noise has stopped thankfully. My neighbour has arranged for her son to come tmrw afternoon and take her down to the local Merc specialist

This is when you really get benefits from being a member of such an informative forum

Cheers and thanks again.

 

[Twistedmind]

Pop the wheel off. Take off the wheel liner. Install a new siren 82 quid from mb.

Just done mine !

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