I have an 83 300 SD that I have been quickly falling in love with. I have seen a number of posts regarding the door lock vacuum system. But not the ones that answer my question yet. So, I will post in hopes of someone out there that can help me.

Problem:
The key locks and unlocks the driver side door only. The rest of the locks need to be pulled up and down manually. The trunk remains unlocked always. The key does not work on the trunk or the passenger side.

Attempt #1
I dismantled the driver side door as per one post recommendation as a starting place to find where there might be a vacuum leak. As it turns out, I unscrewed, and pulled out the blue vacuum component (Swiss made) and found that no hose was connected at all, and the electrical plug was wrapped in tape. Out of curiosity I unwrapped the electrical piece and plugged it into the blue vacuum component and heard a 'click'.

I looked around and found that that action caused all of the doors to lock, including the trunk. Now, I can't get my things out of the trunk. Nice work eh...

I did some minor exploration under the driver side floor mat and decided to seek advice. There are yellow hoses attached to the vacuum locks on the other doors.

I imagine, all I need to do is buy some of that yellow hose and a coupler and reattach it to the driver side blue component and find where it joins the three way splitter, which I imagine is somewhere between the door and the floor mat hosing.

Before I do so, I would love for someone to give a heads up and let me know if I am on the right track.

Thank you,

Tasty Doubles