One thing that I always disliked on both w201 and w124 is the fact that if you are inside the car and lock all the doors, if you want to let someone in, you have to open your door to unlock the central locking system...
I took a look at the electric diagram of the car and I think that with a simple 2-way push button I can have in the console a Lock/unlock button for the central locking system!
The trick is to just use the button to send a 12V or a Ground pulse to the Blue wire that goes to the Central Locking Unit, this way we bypass the door actuator!
What do you guys think?
I'll give it a try maybe tomorow, if it works I think I have a spare defrost button lying around...would be perfect for the console!