Lux,
You do know there is NO vacuum actuator, or even a vacuum line, to the lock in the driver's door on a 1982 300SD.

To unlock the driver's door on the first generation 126, using keyless entry, you must either put an vacuum actuator and line into that door, or piggyback an electric actuator onto the lock rod.

The electric actuator will then signal the pump, thru the driver's door lock microswitch.

Pindelski.com has a 52 picture write-up on this; well worth the subscription price.

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)