Body and Interior Specific Aid

Not sure how to explain this, so apologies up front. In the process of repairing my vacuum door lock system I ran into an issue with the front passenger door. It's different than the other doors. It appears that MB designed this door system to allow you to open the door while the other doors are in locked mode. I think there is a part missing on mine (maybe a spring). The actuator pushes (unlocks) the door knob (stem) up, but when the actuator pulls (locks) the door knob (stem) stays up.

To do some repair work in the rear seat area I took out the rear seat belts. I am trying to put them back in but cannot get them to release. After I removed them they rolled up most of the way and they will not unroll far enough to reach all the attachment holes. The ones I am using are from a 1991 420SEL. What is the procedure to get them to release. Thank you.

1982 300sd - heater blows warm for about 5 minutes then heated air turns cool. should i replace monovalve, then try solenoid that activates. turning heater to off then back on sometimes results in heat flowing again, but not always. turning car off then restarting returns heated air. i think malfunction in monovalve, but solenoid may be at fault as well. how do you diagnose which piece to replace or both? any sources for solenoid besides dealer?? i noticed you are sold out of solenoid

I put new glow plugs, new batt,new relay, new strap fuse on my 123. Key turns it over but indicator light doesn't go on sometimes. Before I replace the ignition switch, should I first check the trans solenoid and neutral safety switch? Thanks