Automatic Door Lock Problem
 

1982 300SD, W126 - Automatic door locks used to work, but not any more.

If I unplug the vacuum supply pump (it's in the trunk) and then plug it in again, it begins to cycle. After a few moments, it stops. If I try the key in the door, the pump doesn't come on again, and the doors and trunk don't unlock or lock. If I unplug the vacuum line from the pump (the yellow line), the door locks don't open. Nothing happens.

Can anybody help?

Aloha,