The pane break sensors are merely a glass-mounted circuit, similar to a heated rear window element. On the Zafira, they are sited in the rear quarter windows & the connections are found at the lower rear area. They can be easily bridged with a "blade" style fuse, to eliminate them from your inquires.
The Power sounders seem to give problems after several alarm events have occurred. Although they have a rechargeable cell inside, they don’t take to kindly to being discharged & need to be replaced. They also need re programming which requires the 4-digit security code.
The codes I found (on the Launch) were…
121 Alarm siren no response 124 Pane break sensor open circuit
Code 121 didn’t clear until the power sounder was replaced & re programmed.