Tooling apparatus configured for preparing a harness of large cross-section; the harness to be prepared comprising at least one conductor cable with a starting end and a terminal end, the harness to be prepared comprising at least one starting connection member and one terminal connection member which is designed to be attached to the terminal end of the cable of the harness to be prepared; said tooling apparatus being configured for shaping the harness to be prepared and for receiving at least the starting and terminal connection members and for placing at least the starting and terminal connection members on the harness to be prepared, respectively at the starting end of the harness and at the terminal end of the harness, said tooling apparatus comprising a work surface supporting a plurality of harness-holding modules, including at least one inlet module configured for holding the starting end of the harness to be prepared and at least one outlet module configured for holding the terminal end of the harness, characterized in that the outlet module comprises an outlet body, on which at least three tools are mounted, said tools including: - a first tool configured for marking the cutting length for the cable of the harness to be prepared and for marking at least one stripping length for the terminal end of the harness, - a second tool configured for marking the position and the orientation of the terminal connection member of the harness to be prepared, said second tool comprising first positioning means for positioning in the crimping position which are configured for positioning the terminal connection member in the crimping position, - a third tool configured for checking the position and the orientation of the terminal connection member of the harness to be prepared, after said terminal connection member has been crimped, said third tool comprising second positioning means configured for receiving the terminal connection member of the harness to be prepared in an orientation of the terminal connection member of the harness after crimping, the outlet body being movably mounted on the work surface so as to alternately present the carried tools (22, 28, 30) opposite an arrival position in front of the outlet module of the terminal end of the cable of the harness to be prepared. - a first tool configured for marking the cutting length for the cable of the harness to be prepared and for marking at least one stripping length for the terminal end of the harness, - a second tool configured for marking the position and the orientation of the terminal connection member of the harness to be prepared, said second tool comprising first positioning means for positioning in the crimping position which are configured for positioning the terminal connection member in the crimping position, - a third tool configured for checking the position and the orientation of the terminal connection member of the harness to be prepared, after said terminal connection member has been crimped, said third tool comprising second positioning means configured for receiving the terminal connection member of the harness to be prepared in an orientation of the terminal connection member of the harness after crimping,