A surgical device adapter assembly comprising: a tubular housing having a proximal end portion configured to couple to a handle assembly , and a distal end portion configured to couple to a surgical end effector ; an electrical connector disposed at the proximal end portion; an electrical contact assembly disposed at the distal end portion; and a wire harness disposed within the tubular housing and interconnecting the electrical connector and the electrical contact assembly, wherein the wiring harness is a flexible cable having a first flexible dielectric substrate , one or more conductive layers disposed on the first flexible dielectric substrate , and a second flexible dielectric substrate , wherein the one or more conductive layers are enclosed between the first flexible dielectric substrate and the second flexible dielectric substrate; wherein the adapter assembly further includes a switch actuated in response to the surgical end effector being coupled to the adapter assembly; wherein the flexible cable is coupled to the switch and includes a flexible finger coupled to the electrical contact assembly; and wherein the surgical device adapter assembly further comprises a rotatable lock member at the distal end of the adapter assembly configured to engage the surgical end effector. a tubular housing having a proximal end portion configured to couple to a handle assembly , and a distal end portion configured to couple to a surgical end effector ; an electrical connector disposed at the proximal end portion; an electrical contact assembly disposed at the distal end portion; and a wire harness disposed within the tubular housing and interconnecting the electrical connector and the electrical contact assembly, wherein the wiring harness is a flexible cable having a first flexible dielectric substrate , one or more conductive layers disposed on the first flexible dielectric substrate , and a second flexible dielectric substrate , wherein the one or more conductive layers are enclosed between the first flexible dielectric substrate and the second flexible dielectric substrate; an electrical connector disposed at the proximal end portion; an electrical contact assembly disposed at the distal end portion; and a wire harness disposed within the tubular housing and interconnecting the electrical connector and the electrical contact assembly, wherein the wiring harness is a flexible cable having a first flexible dielectric substrate , one or more conductive layers disposed on the first flexible dielectric substrate , and a second flexible dielectric substrate , wherein the one or more conductive layers are enclosed between the first flexible dielectric substrate and the second flexible dielectric substrate; wherein the adapter assembly further includes a switch actuated in response to the surgical end effector being coupled to the adapter assembly; wherein the flexible cable is coupled to the switch and includes a flexible finger coupled to the electrical contact assembly; and wherein the surgical device adapter assembly further comprises a rotatable lock member at the distal end of the adapter assembly configured to engage the surgical end effector. <EOS>