Have problems with trunk lock acctuator. Some times it works an some times it don't. But can here the acctuator trying to release the lock but nothing happends.
how to acctuators go bad. Not voltage or bad ground.

 

It's a simple job to fix. (1st on search)

I'm betting they could also go bad mechanically, but it's just a guess...

 

I had the same issue and turned out it wasn't the Actuator at all. Check to see if the trunk light come on when trunk is open, also check your license plate lights. If any of these is not working, then the wires inside the wire loom for these is damaged. I have a 05 and the wire loom is located inside the plastic cover plate on the left hand side of the trunk hinge. Just examine all the wires and you might see the damage one. Hope this helps Good luck.

 

Good point about the trunk light & license plate lights working--check fuse #6 if not.

 

The engineers didn't take in consideration placing these wires there (trunk hinge) would put a lot of stress on these thin wires inside the wire loom over time.