1989 300E Locking System Failure

I went to lock my doors this morning and the vacuum system did not lock all the doors, only the drivers door. I am aware that there is a box under the back
seats that has something to do with the system. Is there any adivce, you guys could give me on how-to repair the problem....?
-Thanks
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

the doors, only the drivers door. I am aware that there is a box under the back seats that has something to do with the system. Is there any adivce, you guys could give me on how-to repair the problem....?

Make sure all of the locks are properly lubricated.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.