Door lock question

Have been trying to get to the bottom of my door problem this morning; The nearside rear door does not open, or unlock on the central locking.

I've got the door card off (RIP plastic clips...) and have taken the B pillar plastic panel off to access the wiring. There is a constant 12v on the red and the red and yellow wires at this point, however there is no constant 12v at the door lock connector block, when I try to unlock the door on the key fob, there is a signal sent to the door lock though.

My question is, should there be a constant 12v at the door lock? or does that stop at the control module in the door?