Spooks in my 98' E200 Alarm

[Axcontrols]

I've had my E200 for just over 5 years. Ever since I had it the alarm would go off within 30 seconds of locking the car. I simply got in to the habit of pressing the switch on the dash before locking the car (The switch, I believe, deactivates the movement sensor). No problems there then.

Yesterday I left the car unlocked with the key in the ignition for around 4 hours. On returning to the car I first went to the boot but found it locked. Tried the little pul-up switch in the centre console but that didn't work either. USed the KeyFob to open the boot worked fine.

Drove home, pressed the little button on the dash to deactivate the movement sensor (Remember i got into the habit of doing that otherwise the alarm goes off after 30 seconds or so) The LED on that switch usually flashes when I press it. This time it didn't. Locked the car, unlocked it again and pressed the switch. Still no flash. So, locked the car and went indoors half expecting the alarm to go off in 30 seconds. It didn't.

4 or 5 hours later alarm siren goes off. No lights flashing, just the siren. Sounds for a short while then goes of for a few seconds and then sounds again. None of my keyfobs work although when I press the fob to open the door the interiour light comes on as usual but the doors stay locked.

Opened the car with the metal key, inserted keyfob into ignition start car no problem but alarm still going off all the while.

When I used the metal key to open the driver's door none of the other doors unlocked.

Disconnected the battery, siren still going off but after a while started getting quiter. I guess the battery in the siren ran out eventually because the neighbours went back inside.

Anyone go any ideas before I reconnect the battery ?

Question. Where is the siren? Can I disconnect It (So that I can drive the car to the dealer without the siren going off)

 

[Parrot of Doom]

Take it to an alarm specialist, it'll be cheaper than the dealer. Your original problem sounds like a faulty movement sensor.

 

[Axcontrols]

Reconnected the battery and siren didn't go off. KeyFobs work as they should.

Most strange.

Anyone else got any thoughts?

Is it all going to work fine till haloween next year ?

I really don't want to take it in to get looked at unless there's actually a visible fault. I've owned cars too long to be daft enough to take a car it to get looked at that isn't actually showing a fault. Too many wanna-be mechs simply change stuff which they 'think' might help and don't take the 'stuff' back when it turns out it didn't.

After all these years I now know why I'm not rich. (Driving a 98' E200 instead of a new CLK) I used to work in IT support/maintenance. I never replaced something unless I was sure it needed replacing and never raised an invoice unless what I did actually fixed the problem.