See at page 8. The 3 pins are for the connection of brake and reverse light. The middle pin is the postive on and the left and right pin for Brake/Reverse which are minus. Us a JR/Servo cable and run the postive pin to each bulb and connect the minus cable from the bulb back to the controller and connect with the right or left pin.
http://www.servonaut.de/shop/media/p...1377874409.pdf