W202 alarm fault

[jasons]

Hi I think I have a fault with the alarm on my 2000 w202,if I have the interior light set so it doesn't illuminate when door is unlocked the indicators flash 3 times when the car is locked which I assume means the alarm is on,but when I have the interior light set so it does illuminate then when I lock the car the indicators don't flash on locking the car,so I assume the alarm isn't on does that sound like a fault and if so does anybody know what could be wrong.

 

[Dec]

Having the dome light set to on or off wont have any effect on the alarms ability to arm itself.
If when the car is locked, and there is no 3 flashes then it should follow that when you unlock the car there should be no 1 flash of the hazards.

Test the alarm by locking yourself inside the car, don’t move for 60 seconds to allow the alarm to arm itself then open a door/s and or bonnet, alarm should sound and hazards flash, unlocking the car should disable the alarm.

The alarm siren, which houses the alarm system, usually dies when the are about 10 years old or the some times partially function and can cause all sorts of weird symptoms.

Example of what can goes wrong here… Alarm / Siren Issues : Goes off for no reason/Kills Battery FIX DIY.. - MBWorld.org Forums

Dec

 

[John Jones Jr]

Good man Dec.

 

[jasons]

Thanks for the reply,even when the hazards don't flash 3 times they always flash once when unlocking the car.

 

[Dec]

If the siren is the original factory fitted unit and has not been replaced recently then the siren is the main suspect, you still need to establish it actually sounds off when triggered.

Dec

 

[jasons]

Thanks I will check it out.