The bottom of the cabinet has a 3/4" air space between the floor of the cabinet and the finished face underneath, that the existing light is mounted onto. The space goes all the way, unobstructed, between the forward end of the cabinets (near cab) and the aft end (near kitchen). I drilled a hole near the forward end (behind my added valence) and fished the wire from there to the hole where the existing light is mounted, and where the wires are accessed. The valences were mounted to the bottom of the cabined about 1" behind the existing light fixture.