New Battery
Then New Alternator
Then flickering lights (you do not say which lights)
Then another New Alternator
Can it be an electrical fault?
It can only be an electrical fault - and in all my motoring since the 1970s I have never had an alternator fault - nobody I know has ever reported an alternator fault - if asked to guess I would say that you have never had an alternator fault either.
The light that tells you about the battery charging or not - i.e the Battery Not Charging Light - is On when the battery isn't charging and Off when the battery is charging - unless....
Unless that is - that there's a problem with the lamp itself or the wire that runs from the lamp to the alternator - the exciter wire. If this is open circuit (broken lamp or bad connection on the wire) the alternator gets no excitation current and does not charge the battery - you will not know about it because the lamp stays off - the battery runs flat.
Before more expensive alternator work have the exciter wire and the lamp investigated - you never know - it may be down to just a dodgy bulb or bulb holder.
BTW - there are people on here who might say that you have this problem because you have a French car - there may be some truth in that but I couldn't possibly comment.
Good luck...
May 2015