It's not a known problem.
If it's going to work, there is only one position of the stalk to try - away from you (forward) ONE click.
There are 2 fuses for the rear wiper - a 5A (#15?) and a 20A (#45?).
One owner, with a new to him X3, found the 20A fuse was missing from his X3.
You don't say if you have owned from new, or how long it is since you know the rear wiper was working.
If both fuses are present and good, next things to suspect:
- the multi-function switch
- wiring connectors around the tailgate
I'd only suspect the motor if the 20A fuse is blown.
ADDED Sept. 12: Wonder if we will we hear from bullittprod again?
Last edited by Supercourse; 09-12-2010 at 06:25 PM.