sunroof on a 190e

please,please help i just bought a 1985 190e 8v.the dealer
just bought a new motor for the sunroof,but explained the cable was bad,so i read some posts here and got 2 looking,my problem
is that the cable is unhooked from the roof i removed it and if i feed through the motor while hiiting the switch the cable seems 2 work fine both ways through the motor but i have to hold the cable,if i let it dangle it wont grab either way,is this normal?should i change the cable?is there a adjustment?finally where does the cable hook 2?it looks to me like it connected to the rear middle "black crossbrace"and should the sleeve the cable goes in be visible from the roof with the trim off"headliner".mine seems like the cable would have to loop around to connect to that brace that seals the roof,but then it seems the sunroof wouldnt pull evenley thanks in advance steve

p.s. there was a spare motor assembly with the plastic gears ,brackets,and electronics,its defenitley not for mine "190e:
i beleive its for the sunroofs that pop up in front & back like i have heard about from this site,FREE to a good home and somebody who can shed some light on my problems thanks