serpi star alarm on W124 1990

[Wizz Jones]

Hi Folks
I've just bought a 1990 W124 260E with a Serpi Star alarm
I wish to disable it without upsetting the central locking system.
I have found the control box in the passenger front seat foot well but there are so many wires! Also I don't know what the function is for the key that fits in the top of the siren - doesn't seem to turn it off! Can anyone help?

 

[Dec]

If tested, does the alarm go off or does it work at all?
Is this a remote fob operated system or a key in the door operated system?

It is likely the siren key should switch the whole alarm system “OFF”, it might also stop the central locking working, best thing to do is turn the siren off with the key then lock yourself in the car, wait for 30 seconds without moving then open all door to see if the alarm will go off.

You need to test again with the alarm turned “ON”

Dec