My 86 300E also has the MB standard vacuum lock system (expensive to manufacture, expensive to repair, and outdated). When I had a keyless entry/alarm system installed, I wanted to avoid wiring into the vacuum pump for fear screwing it up by the unusual operation. Instead, my installer hooked up a cheap electric solenoid to the door lock in the driver's door - initiation of the system now treats the signal as if a key was being used. It has worked fine for 2 years, and the installer has used it on every MBenz that he has since worked on.
THE BENZMAC DOES NOT AGREE WITH ADDING ACTUATORS TO YOUR CAR!!! I HAVE SEEN TO MANY INTERFERENCE PROBLEMS WITH THIS IF THE INSTALLER IS NOT TOP NOTCH!!! AND MOST AREN'T.
[This message has been edited by Nick Jamal (edited 04-06-99).]
[This message has been edited by Benzmac (edited 04-06-99).]