There is a switch in the cab with the engineer - take a close look and you will see it. There are generally 3 modes:
1 - Engine completely off
2 - Lights only
3 - Lights and motor
I can't remember what they are exactly. Also, Swiss engines are a bit different in that when the loco is going forward (or reverse) one light at the opposite end remains lit. You should see this on your 2045 as well.