Bleeping Noise - Any ideas?

I have just finished fitting some seats in my car when it started to make an intermittent bleeping noise, it sounds like an alarm of some sort but I can’t work out what it is. I have tried setting the alarm/immobiliser but it still bleeps, I have tried leaving it with the alarm/immobiliser off and it still bleeps. The engine starts and the bleeping continues I have also disconnected the battery and it still bleeps. Please does anybody know what it could be, it’s driving me mad

Thank you


the s1 had a alarm senser fitted to the back wall just above the hand brake…it is a small black box with a single wire going in to it…make sure you have not disturbed the connection of the wire going in to the box!

Thanks Sean, just been out and twiddled the wires and its stopped!!