w202 Alarm Makes No Noise? :S

[stuart_hatch]

I Have a w202 C250 Sport and last week a nice scumbag decided to thrown a brick through my window and pinch my jacket from the boot (which had its cover over it at the time.

Thing is the alarm never made a sound, the indicators just flashed :S

Any sugestions? The battery was disconnected recently too install tow bar electrics if that has anything to do with it?

 

[joe bloggs]

If earlier mbss alarm is fitted the siren under the bonnet may be switched off, the rest of the system cannot be switched off. Key switch on rear of siren.

Later cars (newer electronic ignition key) had some problems with the terminals of the siren corroding, usually meant the siren would sound at odd times (as the unit thought someone had disconnected it, so would sound off with its internal battery..untill it ran flat and stopped working)
Cure was a new siren and connector.