Hi. Does anyone know where to find wiring diagrams or even factory manual for this type of Ducato? I'm trying to find out root cause for loudly twittering relays which most likely belong to glow plug system. There are two relays, Italian make, Bitron 1328530080, in a relay rack on co-pilot's side under the dashboard. They are making noise only when the engine is running. I believe the relays are not the guilty ones but the root cause is somewhere else. Maybe a dead sensor or something like that. Instructions would make it easier to spot the error.