[Spridgets] (no subject)

[Guy R Day]

As Rick says they are an infra-red device and can fail.
However, a common fault is spiders walking across the face of the sensor. 
It is often worth taking the cover off and giving them a quick clean or 
blast of air (from the compressed air cans used to clean out electric gear) 
and re-checking.  You may find the one outside that works has a weatherproof 
case and small crawly beasties don't get inside.
There should be a small switch inside them that will turn the visible light 
off if you don't want them to be seen.  There are normally only two wires 
feeding them so replacement isn't too difficult - mounting them is often a 
greater problem.  If it is replaced make sure you get the correct patterned 
lens for the area it has to cover.

Guy R Day