We present a motion strategy of parallel jaw gripper for picking a Molex® cable from the flat table before the cable harness assembly process. For robotic assembly of cable harness, the gripper needs to grasp the cable on or near the solid connector part, which conventionally requires precise measurement of the connector location. Our method relies on the relatively rough visual image to find the pose of the cable on the flat table. Fingers of a parallel jaw gripper are opened and placed at a location where the cable is placed between two fingers. Our strategy is to grasp the flexible part of the cable loosely, and the fingers slide along the cable to reach the solid connector part, then fingers push the connector part again a straight bar to fix the grasping orientation. In this way, the gripper can grasp the cable at the adequate position and pose for assembly. We show such a sliding and pushing motion strategy and provide experimental verification.