When you make up your engine consist , each unit has a light selection switch on the inside rear bulkhead panel that allows that unit to be in the short hood , long hood or middle setting.
If you have three units your lead unit (if facing short hood) will be in the short hood position the middle unit in the middle selection and the rear in the either the short or long hood selection , according to the way the unit is turned.
And trailing units in the consist , must have the lights on the control stand in the off position .
Number boards usually have a simple up or down switch for each number board.
On lead units the step lights at night should be eliminated according to the FRA . I've seen some rebuilt units come out of the shops without steplights.