Thanks everyone for your replies, sorry I've not updated sooner.
So after reading all the replies I went back in this week with a few ideas and eventually traced the fault to a blown aux fuse. Pir's had no voltage leaving the tamper as an open circuit.
I must of done this in my attempt to...
Hi Everyone,
I have officially thrown the towel in and declared i'm out on an alarm.
I have fitted a challenger ap11led alarm on a mates garage as a favour after it was broken into. All worked ok for a year until in my wisdom said I would fit an additional external sounder. All has gone to...