BMW Repair: 95 BMW 325i backrest locking, drive cables, bmw 325i

Question
My driver seat remain "locked" in the upper (vertical) backrest position - when pressing the control button on the side I can hear the motor working but there is no motion of the backrest (expected to tilt backwards). Two days ago I went to a dealship and was told that "it's not cables" and that it might be "motor" or "frame".

Since I found that a bit strange (broken electro-motor doesnt make the sound of a working motor :-) and the passenger seat was OK, I tried tilting it back-forth to figure out the mechanism and when I brought it to the lowest position (reclining) it remained in that position - the same sound of the motor, and no motion. So, it definitely seems like some mechnaical allignment which gets easily decoupled in either of the extreme positions or maybe there is some kind of latch?

I tried two BMW maintenanace books, but they both spent a mere half page on the seat and just went about taking it in and out, so one thing I'm alos looking for is some kind of schematics to show me what's inside, how to go about opening/closing, and then how ho fix the actual problem and hopefully do something to prevent it in the future - like something to limit the motion a bit so it stops a bit early or doesn't loose whatever mechanical coupling there is inside.

I'm not exactly a mechanic and don't have a workshop, but I'm pretty sure that with a drawing and a list of a few tools to buy I could handle it, and dealership estimate is so high I think I can buy 5 sets of tools and a few spare parts and sill be in the plus :-).


Answer
it is most likely the drive cables for the back rest. they tend to pop out when they get old. look under the seat and they should be visible to you. you'll see the motors for the seat adjustments. just determine which is for the backrest and look for the cables from there