Digi-set indicator light

I have a client who has one installed to periodically drain a line; however, we are having problems with the overall system and are trying to troubleshoot. Is the indicator light supposed to always be on or only when the switch is active?

Welcome to the Digi-Key TechForum jeremy.pavlish!
A panel indicator light will light up when the right power is applied to it.
So when it lights up, depends on how you have it wired up.