My experience with the small VDO assembly may save a fellow BMW owner the purchase price of a new one, which is $20.95 from Electrodyne, Inc.
One day I pulled the stalk for "wash." The wipers made a few passes as usual, but no water. Upon checking the wiring to the pump motor with a test light to insure that current was reaching the motor, I was satisfied the motor was the problem.
I removed the whole assembly and applied a liberal amount of oil into the capped oil point at the end of the small motor shaft, and let it set overnight. Sure enough, on jumping the motor off the battery the next morning it jerked a couple of times, then ran contentedly.
As preventive maintenance, a drop of oil there occasionally may help. But if your motor has already Seized, try my way before you spend your hard-earned money.
Author: Max M. Geiger