1987 244DL and the central locking works fine. lock the driver's side door and all 4 doors and the trunk lock, unlocking the driver's door though only unlocks the doors and not the trunk. this is a very minor problem but its just annoying enough for me to ask if this is how it's meant to work because I didn't see anything about it in the owner's manual I have. if that's how its supposed to work then I can just deal with it

 

It depends on what position the trunk lock is in, vertical or horizontal, pretty sure it is covered in the owner's manual.

 

Yeah, you're correct, when it's connected to the system, it locks but doesn't unlock. My guess would be the wires from the driver's lock because I remember those being pretty rough. Is it just a single wire running from the trunk to the door lock or are there any other electrical systems in between?

 

when the trunk lock cylinder is in vertical position it should lock+unlock via the drivers door switch. mine only has one blue wire running to the back. not sure why yours would lock and yet
not unlock. you may have to dig further.

 

I was doing some testing and it doesn't lock every single time when vertical so I assume it's bad wiring in the lock, maybe when its pushed down it has enough play to complete the circuit and it doesn't when the lock is raised, I have no clue. I'll pull my doorcard soon and check it out.

 

perhaps the first place to look is the drivers side trunk hinge where the wire loom travels through up to the front. my trunk lock wire broke right there so the automatic function is currently out of action...