Wonkey Donkey - you got it right. The manual release cable was sticky. Shifting the motor positions was causing the cable to change tensions, which explains the intermittent operation of the motor. Thanks for you suggestions!!
2007 Z4 top stopped working. Rear motor would run, but no movement.
Hydraulic motor was sitting in water like everyone else's. The hydraulic motor was replaced. Top functioned with new motor while on shop floor.
Once installed, top would not move, although motor running strong. Motor was...