The drivers electric door lock will lock but will not unlock. You can hear clicking in the door when you move the lock unlock button and with the remote but it wont unlock you have to pull up on the button hard and work the switch back and forth to unlock. What would cause this problem?

 

Sounds like a faulty motor , It takes less power/torque to lock the door as it pulls down the linkage, However to unlock it it has to move the linkage over center

 

it is your door lock acuator ..