Stupid Question Alert: What is the purpose of this lever in the SD9?

[NeoPyro]

Hello Guys,

What is the purpose of this lever?

Ryan

 

[Roy3b3]

Stupid answer coming!

It's an spare lever in case one of the others don't work?
Roy3b3

 

[ThePoliceman009]

I think that's the reverser lever.

 

[norfolksouthern37]

That is the mode select lever or simply 'selector'. It is used to change from inactive (off) to power mode (1-4) or dynamic braking mode (B).

'OFF' is used for locking the controller in unattended or trailing units.
Normal running is done in mode 1, the other modes are to cause transitioning on some older style units that did not do so automatically.