Power Locks on 84 mercedes

I have an 84 Mecedes 300 SD.  I recently bought an Alpine SEC-100S Alarm system for it.  I'm having trouble figuring out how to wire the remote lock/unlock into the power locks on the car.  I've looked at your diagrams and still don't understand exactly what to do.  My alarm system has one lead for a 3 second lock pulse and one lead for a 3 sec unlock pulse, both of which can be configured to be either positive or negative.  I've checked out the voltage on each of the wires that comes from the driver's door to the vacuum pump, and there is one that changes from a constant +12 volts to nothing, depending on whether the doors are locked or unlocked.  What do i tie into for the alarm system to lock and unlock the doors?

barrett

I was thinking that since the driver's door controls all the others, that it was the main actuator.  Is that not true?  How did this actuator that you added work?

I understand.  Would you happen to have more information on specifically what type of actuator and how you wired it into the power lock system and the keyless entry?  Thanks for your help.