Mk6 rear door not locking.

[Oliver82]

Hello. I'm new to the forum and any help would be much appreciated.
The rear door will not lock or open on the key fob or with the key in the drivers door. The front doors and the side door do operate as they should. I have tried a different lock on the rear but it's still the same. I have inspected the loom going to the door lock and there is continuity through each of the wires. The block connectors behind the indicator were slightly dry so I have wd40 these. I have checked the main fuses under the bonnet in the cab fuse box and the two 15 amp under the drivers foot well and they are all okay. Finally I have checked to see if I'm getting 12v to the loom on the rear door which I am not. Referring to the Haynes manual the yellow wire and the black and yellow wires are power and the black is earth. Looking at the wiring diagram these wires in the loom feed back to the central locking control module.
Could this be the problem?

[blue estate]

Follow the wiring all the way along and check for chaffing first

[Oliver82]

I will have a look thanks.

[blue estate]

P/s the loom runs along the roof line on drivers side