Can anybody assist? I own a 2010 Ford fiesta zetec. When i bought it a few wekjs ago thwme remote central locking was working fine but it got to the stage where i had to be standing by the drivers door to unlock the car so i assumed the battery in the fob needed replacing so i changed the battery but now the remote locking wont work at all. I can unlock the car using the key in the drivers door & the car starts up ok? 

Have you put the battery in the right way round it's easily done and some manuals showed it the wrong way round. At least it's easy to check

Just recently changed the batteries in both my key fobs and found one didn't work, even though the batteries were from the same pack. Replaced again with another and fine.

So it could be as simple as a dud battery, a greasy fingermark when you changed it, or battery wrong way round as Pete suggests - easily done.

1 hour ago, Eric Bloodaxe said:

Just recently changed the batteries in both my key fobs and found one didn't work

 

I have no idea why folk never test the battery that comes out of any device they own. (I replace alot of watch batteries for friends/family) You can buy battery testers/multimeters so cheaply these days. If the battery is a dud, at least you know. If it turns out to be good, you know the problem lies elsewhere, and it stops the eternal guessing game...

11 minutes ago, StephenFord said:

I have no idea why folk never test the battery that comes out of any device they own. 

Lol, that's how I knew one was a dud! Next time I might be smart enough to test it before I put it in the fob though!😀