On the Cockpit Chrono Pack, just to the left of the indicator lights, is a small transparent circle. If you pull off the face, what's behind it looks like either a "traditional" clear encased LED *or* some kind of light sensor. It's definitely different than the other LEDs... see attached photo. I can't recall if I've ever seen this illuminated... and the owner's manual doesn't say anything about it...

Anyone have any thoughts on what this is? I'm having a custom face made, and am trying to figure out how to handle this one feature...

 

Light sensor to check ambient light and change the LED level for day/night?

 

Definitely looks like a light sensor. I've got the chrono pack too and have never seen that illuminated.