I’ve got an intermittent fault on a door contact on the alarm. Inside are a number of wires and a couple of resistors. Logic says it’s a break in the wire somewhere but I just wanted to know if resistors ever die and if they do, is it a simple dead/alive thing or can they develop intermittent faults?

They don't usually die unless they have been abused. I'd be looking for dry solder joints and breaks in wires before thinking that a resistor had karked it…

cheers, that's what I was thinking, just wanted someone to reinforce that for me.