I have a 99 c70 coupe and the passenger seat does not work nor does it make noise when playing with the buttons.
But the drivers side moves back and forth but no back rest
the back rest does make a clicking sound when i play with the buttons.
i already unplugged the green plug and plugged it back in.
Anyone have any ideas??????

Thanks,
Alex

 

Sounds like two different problems on each seat.
Passenger: Switches inoperative, probably a broken microswitch near the back passenger release lever.
Drivers: Need further testing to resolve. Figure it could be a motor,control module, switch, etc. Have not looked, but you could probably switch parts from both seats to do more testing.