This paper presents an enhanced method to assess the share and location of harmonic sources in radial and weakly meshed distribution systems. The proposed method is based on the Norton equivalent circuit in which the measured voltage and current at the point of common coupling (PCC) are used to represent the customer side of the system with its equivalent RLC components. Several case studies have been prepared to validate the accuracy and reliability of the proposed method in order to estimate the share and location of harmonic sources. Simulation results show that the proposed method can accurately solve the problems of harmonic source localization using the minimum knowledge of network parameters.