O/S/R Central Door Locking Problems

Here's a brainteaser:

I've had a rear door that wont open or close on my Skoda Octavia MK1 2004 via the key fob or manually inside. The wires have continuity from the A pillar to the DCM and lock, so I decided to change the lock as I could see the feeds on the terminal block when the key fob is activated. Unfortunately it didn't work, so I decided to change the DCM, and once again that didn't work. I'm currently thinking I have to check the wires from the A pillar to the front of the car.

I would appreciate it if someone has a wiring diagram or has an idea what all the wires do on the door lock and DCM connector blocks, or has encountered this problem before.

Thanks.