A wiring harness assembly includes a first flexible planar wire cable having a first plurality of separated conductors formed in a first insulating layer comprising a first substantially flat exterior surface, a second flexible planar wire cable having a second plurality of separated conductors formed in a second insulating layer comprising a second substantially flat exterior surface, and a first plurality of apertures formed in the first substantially flat exterior surface and a second plurality of apertures formed in the second substantially flat exterior surface. The first and second plurality of apertures are sized, shaped, and arranged such that an electrical connection is made between the first and second plurality of separated conductors through the first and second plurality of apertures.