If your vehicle is showing power door locks clicking repeatedly without locking, here are the most likely causes and the parts you'll need to fix each one.
The internal plastic gears inside the actuator strip out or the motor weakens over time. The actuator motor spins and slips, causing a rapid clicking or chattering sound without enough force to move the lock rod.
Dirt, dried grease, or physical obstruction prevents the lock mechanism from moving fully. The actuator clicks as it struggles against the physical resistance but cannot complete the locking stroke.
If a faulty switch makes the vehicle think a door is still open, a safety feature may immediately unlock the doors right after you lock them. This creates a rapid lock/unlock cycling that sounds like clicking.
If the door panel was recently removed for window or speaker repairs, the lock rods may have been bent, bound up, or reconnected improperly, preventing the actuator from moving freely.
A weak battery can cause the lock relays to chatter rapidly because there isn't enough sustained voltage to fully power the actuators, often accompanied by dim lights or starting issues.
The main computer that controls body functions may have an internal short or logic failure, sending continuous, rapid electrical pulses to the lock actuators.