Hello. 
Just bought an 06 plate Fiesta Zetec 1.4 Petrol. 
Have done a full service on it and am working out some of the kinks.

One kink is the drivers door central locking. 
The drivers door will lock all other doors when locked from inside the car. But will not lock using the key fob. 
Which part might be at fault?

Thanks. 

Please clarify. When using key fob do any doors lock? Do they all go clunk like they are trying to lock?

And does the central locking work correctly turning the key in lock

Central locking works correctly with key. All doors lock. 
 

Drivers door is only door that does not lock with fob.

Sounds like a single broken wire, most likely in the chassis>door loom.  Though could be the door latch module itself.

9 minutes ago, TomsFocus said:

Sounds like a single broken wire, most likely in the chassis>door loom.  Though could be the door latch module itself.

Hmmm. Bit of a pain then. 
 

I could do some continuity testing from door loom plug to latch module. But continuity testing the other wires from plug to engine bay/ecu might be an issue.

I suppose I could unwrap the loom at the door and have a look. Damn crusty wires. Any ideas which wires/colours are most prone to breakage?

Ive got the wiring diagrams in the Haynes manual. So not too much of an issue to identify the potential problem wires. 

I can't suggest any specific wires I'm afraid.  I'd peel back the cover and have a look. 

Doesn't the Haynes diagram specify which are door module/locking wires?

Nm. Kink figured out!

Discussion of the loom led me to the plug connecting the door to body, which was half hanging out. 

Refitted and tightened, all locks now working as they should!

Thanks for help.