Hi folks. IID tool tells me that the BBUS is faulty. So had a look at compartment to rear of engine bay on driver's side to locate and replace the offending component. Cant identify the part location. There is the brake servo and master cylinder, a bosch electronics box (not the siren unit), bonnet alarm switch, wiper linkage and brake distribution unit (see pic below).
My eyesight is obviously failing as I cant see the BBUS.
Any advice as to how to access the alarm siren unit would be appreciated.

Found it. Offending item removed and replaced.

Where was it?

The unit is located on bulkhead below the abs unit. To access remove front driver side wheel and release plastic inner guard. You should be able to get access by removing bottom screw and clip and just one of the upper crews. If I remember properly there is only one screw holding unit in place.
For info I was having battery drain issues and replacing the alarm unit resolved this.
Also - a unit from a Ford fiesta - exactly the same unit - is the cheapest replacement.