Sorry to hear of your wiper problem – are you aware that wiper linkage has been a well known problem, but usually because the mechanism breaks. It is well documented in the ‘Little Exsis Book’.
The issue seems to have been because the Hymer extension to move the wiper mechanism forward was not properly supported and flexed. There have been many fixes to add additional support. As far as I am aware this cured the problem – it certainly did in my case , thankfully .
I was not aware that spares were available ( as advised at the time by Fiat dealer) so the whole linkage had to be purchased. Naturally most of us that suffered a breakage purchased a complete scrap linkage (mine included a motor both times).
Best wishes ,
Fred