B is dynamic baking on f7 and 1 is to add power i think it the same on the sd 40 haven't drive it yet
I'm not sure which selector lever you're referring to. The rotary switch on the dash is set according to the number of locos in your MU, to boost the dynamic brake control signal. The lever on the stand is 1) for switching to dynamic braking instead of throttle, and 2 (completely optional) manual rather than automatic motor transitions.
It's simply called the Selector Lever, the tutorial/scenarios tell you to move it to 1, 2, 3 or 4. You have to move it in increments, you can't simply move it straight to 4 from 1. Took a pic with my phone..
I would suggest tuning into the stream when I'm sure Matt will go over the controls as he did last week.
The lever is spring loaded so you advance it by one in either direction with each movement. It is used as in the quote below and positions 2 to 4 are for any locos that you are connected to that don’t have automatic transitions for the power, so they shouldn’t be needed in the game.
