A method performed by a computer system, wherein the computer system is arranged to form, using a 3D printer, a three-way connection point adapter for an electrical jack connector mounted at an electrical control unit (104, 112) arrangement comprised with a vehicle, wherein the adapter is provided for allowing a breakout box to be electrically connected in between the ECU and an electrical system of the vehicle, and the method comprises the steps of: - receiving, at the computer system, information relating to the electrical jack connector by acquiring, using a camera, an image or a video of the electrical jack connector mounted at the ECU, wherein the electrical jack connector has a first gender; - analyzing, by the computer system, the received information by performing image analysis of the image or video of the electrical jack connector mounted at the ECU for determining connector features of the electrical jack connector; - generating, by the computer system, a three dimensional model of the adapter based on a result of the analysis of the electrical jack connector, wherein the step of generating the 3D model comprises forming a plurality of contact cavities with the 3D model and the adapter is arranged as a corresponding electrical plug connector having the first gender; - forming, by the computer system and based on the 3D model, the adapter using the 3D printer; - providing a plurality of electrical contacts (210, 212) adapted to be inserted in the plurality of contact cavities; - connecting a plurality of electrical wires (208, 214) to the plurality of electrical contacts; and - connecting the plurality of electrical wires to both of: - an electrical plug connector having a second gender, the electrical plug connector adapted to be connected to the electrical jack connector mounted at the ECU arrangement, and the second gender being opposite to the first gender, and - the breakout box. - receiving, at the computer system, information relating to the electrical jack connector by acquiring, using a camera, an image or a video of the electrical jack connector mounted at the ECU, wherein the electrical jack connector has a first gender; - analyzing, by the computer system, the received information by performing image analysis of the image or video of the electrical jack connector mounted at the ECU for determining connector features of the electrical jack connector; - generating, by the computer system, a three dimensional model of the adapter based on a result of the analysis of the electrical jack connector, wherein the step of generating the 3D model comprises forming a plurality of contact cavities with the 3D model and the adapter is arranged as a corresponding electrical plug connector having the first gender; - forming, by the computer system and based on the 3D model, the adapter using the 3D printer; - providing a plurality of electrical contacts (210, 212) adapted to be inserted in the plurality of contact cavities; - connecting a plurality of electrical wires (208, 214) to the plurality of electrical contacts; and - connecting the plurality of electrical wires to both of: - an electrical plug connector having a second gender, the electrical plug connector adapted to be connected to the electrical jack connector mounted at the ECU arrangement, and the second gender being opposite to the first gender, and - the breakout box. - an electrical plug connector having a second gender, the electrical plug connector adapted to be connected to the electrical jack connector mounted at the ECU arrangement, and the second gender being opposite to the first gender, and - the breakout box.