Rac have advised alternator not working , had in garage, who tested it at length and said ok, car drives ok but once starting to use electrics , either cruise control,windscreen wipers or air con battery is draining with alarms sounding and orange fault lights show . Stopping turning all off and driving again car works fine ..WHY PLEASE
Water and car electrics / wiring dont mix , especially with nowadays set ups . I'm surprised the garage has not load tested both the alternator and battery , simple tests . If the alternator has been or is faulty it will have run down the new battery which may need a charge to bring up to full capacity . Another thought , the wiring and plug to the alternator should be inspected for water ingress.