MK5 Central locks going haywire in HI CUBE 1997 190 2.5

[97transit2.5D]

Hi, when i open door any side the lock opens then closes,ie open with key goes
into latched mode. If do quickly open unlocked door all locks go into CRAZY Mode..open close ,etc....where do you start with this problem...my back lock is vertical down.but thats not to say its not faulty...thks Rick,,NZ
could be short,could be faulty solenoid,can we not disconnect central locks and have a manual opening door??? Thks in advance,Rick,NZ
97transit2.5D

[MinorMatt]

Its normally one of the doors not closing properly. If you disconnect the electrics for each one in turn you will be able to identify where the issue is