Vw wiper alignment

My son’s '04(?)VW jetta wiper motor became detached from the arms when the nut holding them came off. I reattached the arm but now I cannot get the wipers to line back correctly. They either stay flat down and try to go further down or go too far. What can I do?

The Jetta is a 2001.
Thanks for any help.

When you put the wiper arm back on it needs to be on the right spot of the post.  It needs to be removed and replaced higher or lower (left or right) as needed to get it aligned again.  

It is also possible that the splines on the wiper or the post may be worn.  

Good Luck