The non-destructive identification of surface cracks in steel parts has always been an issue of great industrial interest. Among the non-destructive crack inspection approaches proposed in the past is field measurement resulting from impressed current crack perturbation. Obviously, crack detection becomes more challenging as the active sensor dimensions and/or surface clearance become large in comparison to the crack itself. In this paper, the wavelets approach is utilized in crack volume and location detection using impressed current differential measurements involving relatively large sensing elements. Detailed methodology and results demonstrating the advantages of the proposed approach are given in the paper.