"Hark, what light beyond yonder window breaks?"

[CShaveRR]

We had a rule on our service unit (don't know if it's still in effect) that trailing units had to have their cab lights on. Allegedly it was to prevent crews (and/or other uninvited guests) from going back there to curl up.

[ericsp]

It is the locomotive cab light.

I have noticed on quite a few UP trains I have seen after dark, the lights in the cabs of all or most of the trailing units are on. A few trains have all of these off. What is the purpose of leaving them on? Is it to try to make it easier to see Hobo Joe if he breaks in? Is it that whoever serviced the locomotive just did not turn it off?