1995 W124 alarm Problem

[holtons]

I’ve trawled all the posts related to this but can’t find an answer to my problem.

About 10 seconds after locking the door with the key fob, the indicators flash and keep doing so until I unlock the car. I’ve read that this to warn you there is an alarm fault. I’ve found loads of posts about the Scorpion alarm but I don’t believe this is one as the alarm is integrated into the central Locking system, there is no separate fob for the alarm. Some posts suggest the battery in the alarm siren could be dead but I don’t know where the siren is located.

As has been mentioned in a few posts, I looked behind the passenger floor panel for a control unit to try to identify the make but there is only a red box with 154 written on it (see photos) which I believe is the airbag test connector. I’ve also added a photo of one of the sensors mounted on the A pillar plus one of a switch and led on the dash which looks very after-market.

anyone know what type of alarm this is and where the siren might be located?

thanks in advance

 

[Habil]

Might it be a GT123, I've got one fitted on my car, the control unit is in the engine bay, not a good idea. And it has a relay fitted near the steering column that looks like that 154 red box. It has similar light but the movement sensors are different.

 

[holtons]

Might it be a GT123, I've got one fitted on my car, the control unit is in the engine bay, not a good idea. And it has a relay fitted near the steering column that looks like that 154 red box. It has similar light but the movement sensors are different.

Thanks. I’ll look into that

 

[wrdcc01]

If you don't see the unit under the bonnet just jump in the car close the doors set the alarm and listen for the relays clicking that are powering the hazards. It will either be badly located behind/under the clocks or behind the passenger air bag. As an aside, if you don't have a separate key fob then I assume you have factory IR remote locking in which case the alarm is being set by the comfort module or at the door lock switch wire to the comfort module. Is your courtesy light working with the door open, is the boot light working? These switches maybe causing a fault as well as the rechargeable siren battery if it has one. Check under bonnet switch too.

 

[alabbasi]

If you can trace the wires, undo the whole system and toss it in the bin. Aftermarket alarms create so many problems

 

[holtons]

Weird!

So today I followed the advice from wrdcc01. No obvious sign of control unit under bonnet, checked the courtesy light and boot light - both working fine. Car hasn’t got a bonnet light so no issue there. Next I locked the car and was waiting for the hazards to start flashing like they have been doing and ... they didn’t! The alarm appears to be functioning correctly although I’m not sure how I can test to make sure a siren goes off if the alarm is triggered.

i don’t know why it has just decided to behave. The only thing I can think of is I did recently replace a faulty sunroof control switch in the courtesy light control unit. I thought I’d tested the alarm since then - but maybe not!

 

[Habil]

Leave a window open with enough space to introduce your arm and wave it around. If you're alarms working it should go of....

 

[holtons]

Leave a window open with enough space to introduce your arm and wave it around. If you're alarms working it should go of....

thanks. Just been out and tried that. The drivers side sensor detected my arm and set off the hazards and immobilised the ignition. No horn or siren though which I think is odd.

 

[holtons]

i finally sorted this problem. In fact the siren has been ‘hiding’ in plain sight under the bonnet. I can’t believe I haven’t spotted it before, it’s very obvious when you know. I feel a right idiot! Anyway, the siren wasn’t sounding because it had been turned off with the siren key. It’s now fully operational.