This is A Barstow Scenario: Dash to Lenwood
After refueling you need to couple to this first locomotive. Upon coupling up the second loco's lights kick in. All of them. The second locomotive lights will turn off when you turn off your loco's lights. Also when you turn on your lead loco's step/porch lights, the step, porch lights on the second loco turn off and just leave the headlight/ditch lights.

Next you have to couple up to two sets of locomotives on another track, and then things get all sorts of weird.


