I recommend using K4 (relay), but if you don’t, you need to supply power to one of the 12v Out pins.
The 12 V Out pins are for powering the MD13S, 12 V to 24 V converter … and so on.
BTS442E2 is needed, if you want to use Sw Out 12V pins.
Sw Out +12v pin can be used for 6/2-valve (optional) to connect hydraulic steering valve lines to the steering cylinder when autosteering is enabled. Sw Out +12V pin provides +12volts when autosteering is enabled.
I’m not sure, but Sw Out +12v might also be used to supply +12V to MD13S to prevent it’s braking feature when powered but not having any pwm signal coming in. Could someone correct me if I’m wrong?
SJ1 jumper needs to be soldered regarding which motor controlled used.
If you want to use Sw Out 12V as a normal 12V output, you can leave BTS442E2 out and add a thick jumper wire between the pins shown on photo below.
Steer is for autosteer switch/button.
Imp is for workswitch.
Remote is for turn sensor/pressure sensor.
Analog in/CAN/Aux A/D connectors are there for just in case. I would like to hear if someone finds a use for them 
You can leave the R8 empty if you use a simple 2-pole on-off switch on the Streer, Imp and Remote.
EDIT: Corrected wrong part name