I just bought a 79 633 CSi and the sunroof was stuck open when i got the car.  I have pulled the motor loose from the gear in the trunk, and manually rotated the knob in the trunk to try and move the roof, but it sounds like the cable is broken in the c-pillar.  The motor does rotate when the swith is activated, but did not make anything happen with the roof.  If anyone has any experience with these sunroof setups please let me know, as i am at a loss for how to repair this, or even tear it down to see what bad parts i have.  Thanks, NICK