V Reg Zafirra Car Alarm?

I have a V Reg Zafira which has an alarm fault. The alarm is going off intermittently but it sounds really strange (strangled!!!). It sounds as though there is an electrical fault inside the alarm sounder. The horn doesn't operate at the same time but I believe the lights flash. I've managed to disable it by removing several fuses but have now lost my speedo and rev counter. Any one have any ideas