Car boot problem

I have a problem with the boot of my car,
well the central locking really.
The central locking works and locks all the doors.
But when i use it to unlock ,it as stopped unlocking the boot.
I have to now use the key to get in.
It's a mazda 3 saloon.
Any ideas anyone.

 

Dodgey wiring connection, or failed motor in its lock. Or it could just be a bit sticky. When you use the key do you feel any significant resistance?

 

No, the key opens it fine.
All the other electric's seem O.K
Indicators, Brake lights , etc.

 

It could still be a dodgey wire or loose connection. They all share a common negative connection, but each bit has its own positive connection. Thing is, you won't know unless you open it all up to have a look. If its a nice car I would be tempted to not bother, as you will have to remove lots of interior paneling and it can be tricky getting it back on right.

 

Thank you , it's not a big problem using the key, i just didn't want it to be the start of a bigger thing with the central locking.
I'll see how it goes.
Thanks again.