Each connector inside the electronics are also labeled. Extruder goes to the one that moves the filament (with the 4 tubes), selector goes to the one that moves the cams, and the red/black/green should always be placed on the 3pins with the Red towards the center of the 3D Chameleon and the green wire on the outside edge. Both the motors are keyed, so you can't insert them backwards.
Each connector inside the electronics are also labeled. Extruder goes to the one that moves the filament (with the 4 tubes), selector goes to the one that moves the cams, and the red/black/green should always be placed on the 3pins with the Red towards the center of the 3D Chameleon and the green wire on the outside edge. Both the motors are keyed, so you can't insert them backwards.