Help needed please, Alarm/hazard

[steve0]

Help please Alarm/hazard light issue.

I own a 2007 D5 with 40k on the clock and I have been having some issues with my alarm for a while now.

Initially as with countless other owners the alarm for no apparent reason would sound (usually in the night).

Forums suggest that the issue is most likely either

1 - Battery which i have replaced

2 - Siren - The alarm on my 2007 model is sounded through my horn sirens under the bonnet not a separate unit under the wheel arch which i believe is the case on pre - 2006 models

3 - Wifi interference which i have ruled out

4 - MMS unit which is know my last hope

I have managed so far to save myself a trip to my Dealer by removing the 15 amp fuse that sounds the horn when i am not driving the car. This has stopped the noise but does not stop the hazards flashing when the alarm is triggered which has not been a major problem and has served me well for months now.

Tonight things have escalated and i do not know if i have a separate issue or if everything is connected, hence my post for help and advise.

I noticed this evening that my hazards were flashing as per usual when the alarm is triggered but after a pause of no more than a few seconds they would start again and this was constant for well over 30 mins. A series of strange happenings then unfolded -

1 - i try to unlock the car with my key fob and nothing happens (fob seems dead - coincidence?) so unlock the car with the key.

2 - when i open the door an alarm sounds i have never heard before, not the horn sirens as usual (it looks like there is a separate siren somewhere after all)

3 - turn on the ignition key, new alarm siren stops sounding but hazards continue to flash. Turning on and off the hazard switch seems to stop the flashing momentarily but would soon start flashing again.

I have had no other choice than to disconnect the battery which in turn as now left me unable to lock the boot.

I really hope someone can relate to the above issues and point me in the right direction.

Sorry for the long post and thank you in advance for any help.