Hi, the rear door window wipers on my 2008 Scudo van with barn doors went suddenly out of synchronisation during a heavy rainstorm. I was away from home at the time and just left the vehicle parked up for a few days. On the way home in the dry, I realised they had 'parked' properly in the straight up position at some stage while I was driving. I had cause to use them again today (not heavy rain, just light drizzle while moving off) and they went bad again. They are only sweeping sporadically, will not park properly and end up with one or the other angled across the window rather than pointing straight up.
Any ideas on what has caused this and how to go about either fixing the problem or at least getting the wipers back into the proper 'parked' position?
How they synchronise apparently independent wipers anyway is a bit of mystery to me.