Problems with my alarm lamp - S320

[Netrix]

Hello - I have a 1998 S320 with what I believe is a factory fitted alarm.

Recently the lamp on the dash that tells me the alarm is armed has started to illuminate whilst driving.

sometimes it stays on for two or three minutes, other times it just flashes on and off again.

The alarm still functions correctly, and when it's armed, the lamp pulses as it has always done.

Does it indicate a problem elsewhere do you think ??

Any advice much appreciated

Regards

Netrix

 

[frog1520]

Hmm my '97 320 doesn't have a light like that! Wonder if it really is factory fit?

 

[Netrix]

Hmm my '97 320 doesn't have a light like that! Wonder if it really is factory fit?

It's looking that way - I posted in another Benz forum and that is what they have said

Looks like I'll have to find an alarm specialist.

I thought it was factory fit because I have two little "dongles" that fit in a tiny socket in the driver's footwell. I'm told plugging in either the black or red dongle will disable the alarm ? (also told I need the red one if I want a replacement key that works the alrm)

Confused.com !!

 

[Dec]

Have you tested the alarm to see if it works?
Lock yourself in the car, wait 30 without moving, then open a door.

That LED may have a 3rd purpose apart from indicating the status of the alarm as to whether it on or off, it could also be communicating to the driver that the alarm was triggered in some way since the car was last locked.

Is there any pattern to the flashing LED, does it for example always flash the same number of times.


Dec

 

[Netrix]

Is there any pattern to the flashing LED, does it for example always flash the same number of times.

Dec

Hi Dec - thanks for your assistance - I think you may have something there !!
Just locked myself in the car (for the record, I only have one fob, the alarm and doors work of the Mercedes key fob) When armed the led blinks every 3 seconds.
I started to move and the motion sensors on the A pillar flash, they must have a tolerance built in because I had to move continuously for about two seconds befor the alarm went off.

I silenced the alarm, opend the door and closed it again and started the car up - and the damn led now doesn't blink when the car is running !! go figure eh ?

I left the car running for 4 or 5 minutes and it didn't blink once.

I'll be leaving work at 7 tonight, it's a 30 min drive home so that should be a good test. As far as I remember there was no pattern to the led flashing when it shouldn't be - sometimes it was on constant for 20 or 30 seconds.

Thanks again.

 

[Dec]

You really need to go to the dealer with your VIN number and find out what alarm system you have fitted…make/model…and try and source a user manual and the fitting instructions, this will give a full explanation of exactly how the alarm functions.

My own Scorpion alarm LED, similar to your own, will flash a certain number of times to inform me if my alarm was triggered in my absence, can’t remember if this happens when I unlock the car or if it happens when I turn on the ignition, in my case, this flashing sequence and explanation, is as follows;

7 Flashes =attempt to start the car
5 Flashes =door opened
4 Flashes = boot/bonnet opened
2 Flashes = alteration of vehicle reference angel…if an anti-jack sensor is fitted/activated
1 Flash = movement within passenger compartment via ultrasonic sensors.
NB the sequence of flashes will be repeated 3 times.

If your alarm hasn’t been triggered then there may be a fault somewhere causing this flashing LED, try turning the system off for a few hours, a “reboot” might solve the problem.


Dec