Last week I bought a 1997 Z3 1.9. Both the driver's seat and passenger seat have power verticle movement in addition to horizontal. When I attempt to use the control to move the driver's seat up and down, there is only a clicking sound but no verticle movement. The fore and aft movement works fine. The passenger seat goes up and down, as well as backward and forward. Does anyone know if a new up-and-down actuator on the driver's side would solve this problem? I tried to look under the seat but couldn't see anything. Thanks in advance to anyone who can help with the diagnosis.