Cheers for that andy, were to start looking though might be time for auto electrician..
Think I'd take a gamble on possibly someting behind the dash or instrument panel as that seems to be where the faults are focused.
Sorry but I am quite new to Berlingos myself and haven't a clue how you get access or if removal will affect the workings of the instruments like the speedo and mileometer. Such a lot of weird and wonderful gizmos onboard nowadays so don't just launch in or you could cause even further damage...
Berlingo Multispace 2.0HDI '54 reg Mediterranean Blue