1998 Ford Puma central locking

I had a similar thing happen with my Puma, which
I've owned for over 8 years. My central locking stopped working and I assumed the battery in the key fob had died. I changed the key fob battery, but it didn't make any difference and I lived with the problem for several months.

However, the central locking miraculously started working again when I changed the car's battery. It seems that although the car battery held enough charge to start the engine reliably, it didn't have the power to work the central locking.

If you're still on your original car battery, try changing it. It might just be coincidence that the problem started at the same time you changed your key battery.