Help with switching off alarm on Swift 560L 2018 Ducato base

[cb_stalbans]

We are currently in Germany and driving down the Autobahn today loud intermittent alarm noises started playing through the Kenwood speaker in the MH ceiling. We stopped and as I thought it was a Sargent tracker issue I phoned them. Nothing to do with them , but they helpfully called Swift technical support and asked about the factory fitted alarm. They called back and said they had been told there is a brown wire with a purple chase that needs to be disabled. The alarm carried on for about an hour while I drove then stopped. I’m terrified it will start up again on the campsite I’ve just arrived at for five nights. I’ve read the fiat ducato manual about fuses but nothing mentioned. Tried to phone Swift , but no phone only a WhatsApp chat that has been unanswered for two hours. Useless Swift. My thoughts are find the correct fuse and take it out, or remove the wiring at the back of the Kenwood speakers so they don’t work. I can’t work out how to get the speaker front off to access any wires. Can anyone advise on a way forward for two non-technical people?