I've been trying to locate a driver side door actuator for my 89
vanagon. My part number is 255 959 781. Chris at Jordan VW has a part
255 959 781. His has three wires going to it, mine has four. Is it
possible that they interchange, and if so how?

Also, I have a question as to how these things work. I see a clear
plastic tube extending about an inch out the bottom of mine. If I
suck/blow on it, I can get the actuator to move, but water (and most of
the pressure/vacuum) comes out of a crack in the plastic housing near
the bellows, which seem to be in good shape.

What's going on? How do these things work? Should I take a shot at
taking it apart and trying to repair it?

Thanks,

Jim