Old a class alarm keeps going off!

[Bigwill]

Hi all
Yesterday my alarm kept going off for no reason
I had to keep the doors unlocked for a around 3 hrs then all was fine.
This has happend around 6 times now. Anyone else had this happen?
Thanks all

 

[Dec]

Probably the alarm siren, does the below link look the same as your car, you don’t mention the year of your car?
See… Bert Rowe's-A-class info. Information A160/Feb 2002 Scorpion Car Alarm System.

Dec

 

[tonysmb]

You could try eliminating things by individually switching off/deactivating the interior and 'towaway' switches, assuming your car has them.

 

[Bigwill]

Sorry its a 1999 with the Scorpion alarm 1.4.
I don't have a tow away switch and the led/button is broke (when I brought the car)

I've had a look at that site and both LEDs flash as normal but I seen a thread saying in the winter the hot air coming out the vents can set the alarm off when the winter is here. But I don't know about that.
I've only had the car for 4 months so can't say if it did it last winter or not

Thanks for the help

 

[Dec]

Anything changed recently in the sequence of events when you lock the car, do hazards flash the correct number of times when you lock and unlock the car?

Test the alarm by locking yourself inside the car using the remote, stay completely still for 60 seconds to allow the alarm to set properly then open a door/s and or bonnet to see if the alarm siren screams and the hazards flash.

If the alarm siren has more than 2 wires going into the back of the siren then the siren is likely to be faulty and may be causing the false alarms.

If you unlock the car with the remote, you will disarm the alarm, if you then lock the car up manually with the metal key blade in the door/boot lock and don’t use the remote then the car will be locked but UNARMED so no security but you will get a nights sleep as the alarm is unlikely to go off in the unarmed state.

What do you mean the “led/button is broke”, is this a 2 button flip out remote you use to start the car?

Dec

 

[Bigwill]

Anything changed recently in the sequence of events when you lock the car, do hazards flash the correct number of times when you lock and unlock the car?

Test the alarm by locking yourself inside the car using the remote, stay completely still for 60 seconds to allow the alarm to set properly then open a door/s and or bonnet to see if the alarm siren screams and the hazards flash.

If the alarm siren has more than 2 wires going into the back of the siren then the siren is likely to be faulty and may be causing the false alarms.

If you unlock the car with the remote, you will disarm the alarm, if you then lock the car up manually with the metal key blade in the door/boot lock and don’t use the remote then the car will be locked but UNARMED so no security but you will get a nights sleep as the alarm is unlikely to go off in the unarmed state.

What do you mean the “led/button is broke”, is this a 2 button flip out remote you use to start the car?

Dec

The hazards flash once for unlock and 3 times for locked...

The sensors work fine and alarm goes off sane with the doors opening.

Don't know about the wires.

I've locked all the doors with out using the remote and the alarm goes off still lol petrol cap will stay unlocked.
The LED in the car is I push switch that you press and the interior sensors switch off. That don't press.
Thanks

 

[Dec]

Does the alarm sound immediately when you lock or is there about a 10 second delay before it goes off?

Is there any other device that might be used to turn the alarm off or disable the alarm similar to what was in my link above?
The alarm siren may have back up batteries inside the siren which may be causing the false alarms.

Not a lot you can do this time of night other than disconnect the car battery, the alarm might still sound off if it has backup batteries inside the siren.

Will the car start while the siren is screaming?

Dec

 

[Bigwill]

It goes off around 5-10 mins after I lock the car but it's not done it today :s
When it happens it does it for around 2hrs and has done it around 4 times now.
It went off when driving once too lol
Can I just pull the siren out?
I might have to get an alarm guy to disconnect it all I bet it's not £20 to get it done

 

[Dec]

Disconnect the siren, hopefully there is a plug to unplug on the back of the siren.
Do this with the car unlocked, unplugging and removing the siren would stop the noise but it might not stop the hazards flashing and running down the car battery overnight, remember the siren, if it has backup batteries may sound off when the siren is disconnected.

Scorpion may be able to advise of an alarm fitter near you.
See Support page here… SCORPION

Dec

 

[Dec]

In addition to above, is your car battery good, a failing battery could trigger the alarm.

Dec

 

[Bigwill]

In addition to above, is your car battery good, a failing battery could trigger the alarm.

Dec

I've not had the battery tested but it is fully green in the little hole (if you know what I mean)

 

[Dec]

As far as I know your alarm will be similar to the one in link below and consisting of the siren and the alarm control box like the one in the 6th picture of the link… Bert Rowe's-A-class info. Information A160/Feb 2002 Scorpion Car Alarm System.

Disconnecting the control box (as well as the siren) while the car is unlocked may? disable the system, hopefully this wont disable the car from starting.

The control box, if you have one might be located below the dash, behind the panel above the drivers knees, however it could be elsewhere I the car.

Dec

 

[Bigwill]

As far as I know your alarm will be similar to the one in link below and consisting of the siren and the alarm control box like the one in the 6th picture of the link… Bert Rowe's-A-class info. Information A160/Feb 2002 Scorpion Car Alarm System.

Disconnecting the control box (as well as the siren) while the car is unlocked may? disable the system, hopefully this wont disable the car from starting.

The control box, if you have one might be located below the dash, behind the panel above the drivers knees, however it could be elsewhere I the car.

Dec

Thanks I may have a go and pull the plug and let the siren battery runout. Hopefully the car will run. Do you know if its linked to the imoblizer?

 

[Dec]

It could be but I don’t think so as the remote control fob has a chip inside the remote case that interacts with a coil around the ignition lock, once again this site is very useful and explains here… Bert Rowe's-A-class info. Hazard warning, car keys, re-synchronizing remote keys, Central locking.

See also… Albert Rowe Lofty's Homepage,Mercedes-Benz 'A' Class info. Battery replacement siren unit Scorpion alarm Mercedes 'A' Class

Dec

 

[Bigwill]

Ok thanks for your help dec

 

[Dec]

Let us know how you resolve this.

Dec