![]() If you have been following this site for a while, you will have probably realised that there is a little more on the subject to come – there is an option that could save you some money and get your alarm working correctly again, for around a £15 chance investment with some DIY time and a soldering iron. ![]() Replacing the batteries in the siren module / sounder unit If you are doing a straight swap-out with a new component and you have good elevated access, it is possible to replace the siren unit without removing the road wheel – by just undoing the trailing edge fixings of the plastic arch liner and pulling them out of the way while you remove/replace the siren unit. Fitting the wheel and lowering to the ground to complete the job. To replace the siren simply plug in the new unit with the car unlocked and alarm de-activated, re-fix the bracket and build up the inner arch panel. Once the support bracket is free, the siren can be unplugged and totally removed from the car. The rearmost fixing is a strange 8mm crimped nut affair, that quickly removes with pliers. If you don’t have the correct security tool, just tap them round slightly on their outer circumference to loosen with a small chisel or punch, once slack, they will usually remove with firm finger pressure. The torx self-tapping fixings that hold the siren bracket to the vehicle are security types with the inner peg. You should now be able to see the siren, fitted to a steel bracket that is fixed to the bodywork. Simply remove the road wheel, remove the five plastic 10mm nuts and remaining fixings that secure the inner protection panel. On the C Class (W203) it is located behind the plastic protection panel under the left hand (near side UK) front wheel arch. The first thing to do is locate and remove the faulty sounder. A replacement sounder is around £100 from a dealership and once fitted will in the majority of cases, cure any problems you may have. The electrolyte from these cells is conductive, as it spreads, it bridges circuit tracks and components making the alarm system unstable and causing it to do peculiar things. What happens is they start to leak and spread over the PCB inside the sealed alarm unit. The problem with the batteries is not quite as simple as it sounds. It is these internal NiMH batteries that will start to age and deteriorate, giving rise to the conditions stated above. The siren module is a round black plastic canister about the size of a small bean can, containing an alarm sounder, control electronics and back up alarm system batteries. If your Mercedes C Class alarm starts to behave strangely with random false alarms sounding, indicators flashing without any alarm sound or even chirping whilst you are driving, then the number one cause for these issues is the siren module.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |