Vito 109 CDi Rear Central Locking

[FinTal]

Hi, Can anyone point me in the right direction. I have a 2005 Vito 109 CDi van. The rear doors will not lock on the fob or by using the inner button. I have replaced the rear door lock ( Up and over - 1 piece ), I have replaced the door contacts and the ones on the pillars. Not life whatsoever. None of the three doors lock or open when you lock them manually and try the fob or button in the cab.

Any help would be appreciated.

Rgds Roger