A new technique is proposed to reconstruct faulty wiring networks from the time domain reflectometry response. The developed method is also for characterization of defects in the branches of the network. The direct problem (propagation along the cables) is modelled by RLCG circuit parameters computed by finite elements (FEM) and the Finite Difference Time Domain (FDTD) method. Genetic Algorithms (GAs) are used to solve the inverse problem. The proposed method allows to accurately locating wire faults. Some examples are presented to validate and illustrate the ability of this reconstruction method.