[veedubmechanic]

if the line was disconnected in a door, you would hear a sucking noise really loud. If it does make the loud noise than pull off the door pannel and check the line and see if its broken.
Disconnect the line at the pump motor and lock/unlock the doors and see if it sucks/blows. If it doesnt, than disconnect the electrical connector and look for corrosion. Replace if there is.