Alarm fault 01134 issue

[mstirlz05]

Hi folks have had an issue with the alarm siren for a while now. No sound only hazards. This code came up in the carista app.
I have replaced 2 sirens and the fuse but there is still no sound.
Is the harness a common cause of this because I don't want to faff around stripping the wires out if its not going to resolve the issue.
Is there anything else that I'm missing?
Tia