Bmw z3 passenger seat goes forward backwards but

change the polarity to the motor. red to black and black to red> hope this helps you

try new switch or motor

could be. could be a switch or motor. different switch contacts for up/down along with different motor

motor and/or switch

that motor has eithe become jammed or has gone bad. Sometimes u can replace the moor itself or you have to get a whole new seat sub-frame that has the motor assemblies on them already. getting the seat frame is the easiest repair as switching the motors can be time consumiing and difficuly if you loose a screw or washer.

The gear our rotating cable is stripped

Bushings in seat are shot. See this link: http://www.youtube.com/watch?v=DM4KSnA58EI

There is a ratchet system on the slide rail below the seat, sometimes the teeth on the ratchet wear out, especially when adjusted often. The hook holder that actually clamps onto those teeth, may be broken off or worn out aswell, and either of these will need replacement. Some models also come with air-suspension and a locking device, the spring on this device may be missing or worn, this will also mean a new one is neccesary for repair.

BUT... If you don't want to fork out, and are going to leave the seat in one position for a long time, may I suggest simply welding the rail to the seat, this is a permanent thing and would require you to throw away the entire sliding system, if you ever need to adjust the seat. Hope this helps you. Good luck!

hi,seat motor are in maximum length,try to seat,then apply force backward also the switch in backward mode.

its the dreaded seat rock syndrome, plenty of fixes on the forums, basically you have to replace spacers in set drive mechanism. I did with the help of a friend after ordring bushes and it was quite easy.