Hi, Don't know if this helps.... I have a 2007 Ducato.....after barely being able to hear the clicking noise of the indicators, I could not locate the flasher unit to fix up this problem. I believe there is no replaceable unit, as the sound is being made by the Canbus computer.
So if its a lack of sound you are having, maybe this suggestion could help. Buy two small 12 v buzzers from and electrical parts store and install one in each door behind the door speakers. Tap into the wire that feeds the mirror flashers.
See photo