Technical Front Central Locking not working

[paddster62]

Hi I've just recently purchased a 2016 fiat doblo 1.6 maxi, I was told that the front central locking wasn't working and I didn't realise what a bugger it would be with the passenger door, have tried changing the lock mechanism but didn't help. Car locks fine and back door central locking works, but even with key only opens front drivers door. Hoping it might be a relay but can't find out where they might be, any help gratefully received

Paddy