W140 Alarm on the BLINK !

[MajorMerc]

Hi All,
please advise the procedure to re-set the alarm on a 1992 600 SEL. The vehicle was idle for a couple of months and the battery ran down ...... I removed the battery and recharged it. When I refitted the battery the hazard flashers began to blink for a few minutes ...... then stopped blinking ...... then, after a few minutes start blinking again. The vehicle starts and runs fine.

 

[Dec]

When you reconnect a battery it usually triggers the alarm, will unlocking the car not deactivate the alarm, keep it unlocked for some time as there may be a rechargeable battery in the alarm system that also needs recharging.

Dec

 

[MajorMerc]

W140 Alarm on the Blink

Many thanks for the advice Dec. Unfortunately, your prescription has had no effect ..... it really is weird. I connected the battery and left the doors unlocked for several hours in the hope that this would re-charge any 'internal' battery in the alarm system ...... but, as soon as I opened the drivers door the flashers cut-in. The 'interesting' thing is that the car starts and runs fine ..... not a very efficient ant-theft system eh ! When the flashers are active there is no response when the key is turned to the start position (same as when gear lever is in-gear) but, as soon as the flashers cut-out, the car starts fine ...... then when the flashers cut-in again the engine remains running ...... very effective at preventing theft eh !

I failed to mention in my first post that there is a red LED in the panel under the steering column that is constantly lit (when the battery is connected) ....... I had never noticed this LED afore now - either permanently or periodically lit.

Where is the alarm itself located ? I wonder were one to disconnect the plug on the unit and re-connect would it resolve the problem. I am amazed that the owners manual does not contain information about something so fundamental as to what to do after removing and replacing the main battery ! Where can I get a workshop manual for this model ?

MAYDAY !!!

 

[jibcl500]

are the batties in the fob good, if not sure replace them.

jib

 

[MajorMerc]

W140 Alarm on the Blink

Hello Jib,
I believe the key-fob batteries are fine ...... the key-fob opens and closes the car without any hesitation; also, I have used the spare key-fob and the 'result' is the same.

The saga continues !

 

[Dec]

When most cars are unlocked the alarm should switch off, yours doesn’t seem to be doing this, the red light is on probably to tell you that the alarm is armed so there must be a fault somewhere. In cases like this a car will have a means to disable the alarm, usually a key switch located somewhere convenient for the driver usually under the steering wheel or glove box and sometimes at the alarm siren under the bonnet, did an extra small key come with the car that doesn’t seem to have any particular use? If so this might be for the alarm.

No harm in trying to disconnect the plug on the unit and re-connect to see what happens.

I wouldn’t know where the alarm is on your car, the alarm can come in two parts, the Brain and the Siren, some have the Brain inside the car and the Siren under the bonnet and some have the Brain and Siren combined in one unit under bonnet.

As the siren doesn’t seem to be working perhaps the indicators may be going off in an effort to warn you that your siren is faulty and after a set amount of time the switch off and then allow you to start the car and the red light is on all the time to pester you to get the alarm checked, just a thought.

Workshop manual, don’t know if the have yours.

Dec

 

[television]

Your car may have a similar alarm

http://forums.mercedesclub.org.uk/showthread.php?t=42002


The other thing to do is to take off a battery connection and leave it off for 5 mins and re connect, this does sometimes work

 

[robarusia]

Mercedes SEL 600 w140 1992

Hi , my battery went flat once, i replaced it and now each time i open the door alarm goes on. I tried to remove - and + from batery for 10 sec and one time it helped but now again the same. Any idea how to disable alarm? Or restart alarm system ?

 

[robarusia]

Hi , my battery went flat once, i replaced it and now each time i open the door alarm goes on. I tried to remove - and + from batery for 10 sec and one time it helped but now again the same. Any idea how to disable alarm? Or restart alarm system ?

 

[television]

You will need to re sync the key to the car

 

[Dec]

How do you unlock the car, is it a remote, what type of remote do you have and have you changed the remote batteries?

Unlocking the car should disarm the alarm.
Locking the car should arm the alarm.

Dec