How to Replace a Door Lock Actuator
Power door locks are almost universally installed in vehicles today. When you press a button on your door’s interior panel or key fob, the doors lock or unlock at the command. An electric actuator changes the position of the door lock on the latch to either secure the locks or allow the latch to be opened. However, the door lock actuator can fail over time and need to be replaced.
Most door lock actuators are integrated into a door latch assembly, and you’ll find one at each door that has a power lock. Some lock actuators are separate from the latch, and they tend to be less expensive. You might spend around $40 or more than $400 for the part, depending on your vehicle’s make and model as well as which door you need to change it in.
Here’s what you need to know about lock actuators, how to identify a bad door lock actuator, and the steps to change it.
Why Door Lock Actuators Go Bad
A door lock actuator has a small electric motor inside the housing. When the circuit is completed as the power lock is triggered, power is applied to the actuator and it changes position from locked to unlocked, or vice versa. A gear, cable, or rod on the actuator connects to the door latch.
Failure can happen if the actuator is exposed to moisture over time and it gets into the electrical components. Corrosion forms and disrupts the connections, resulting in intermittent operation or complete failure. Oil, dust, and other contaminants can also cause the mechanical portion to be more difficult to move, causing more strain on the electric motor than it should have. As well, physical damage can occur from an accident on the door, or if someone attempts to jimmy the lock. And of course, excessive use over many years can simply wear out the actuator.
As an electrical part, it’s always possible for an unexpected fault to occur. And generally, the causes can’t be prevented from happening.
Symptoms of a Bad Car Door Lock Actuator
If your door lock actuator is going bad or has failed, there are some common symptoms that can signal it’s the culprit:
- One door lock quits working. If it’s only one door lock that stops functioning, it’s likely the actuator is at fault.
- More than one press is necessary. A weak door lock actuator might need two unlock or lock presses to move the lock rod or cable.
- The alarm goes off when opening the door. The security system often ties into the door locks and, when it detects an open door that hasn’t been disarmed, the alarm sounds.
- Door Ajar light stays on. There’s a switch in the latch or actuator that detects an open door, and it may not be working.
- Buzzing or ‘machine gun’ noise when locking or unlocking. A failing actuator might cause a buzz, squeal, or surprising ‘rat-a-tat-a-tat’ noise.
How to Change a Door Lock Actuator
There’s a door lock actuator inside each door that has a power lock. For each manufacturer and model, the process will differ to disassemble and replace the bad part. However, the basic steps are the same. Here’s how it’s done.
1. Disconnect the battery
As with any electrical work, disconnect the vehicle’s negative battery cable to prevent accidental problems. While it’s unlikely to happen, be sure to avoid electrical issues by disconnecting the battery before anything. Make sure the door window is fully rolled up so access isn’t impeded.
2. Remove the interior door panel
Access to the door latch or actuator is from inside the door. Locate and remove the fasteners holding the interior door cup, pull handle, and/or panel. You’ll also need a trim stick in most cases to gently pry plastic clips out without breaking the panel or the clips.
Once you’re sure all the door panel fasteners have been removed, gently slide the panel up and away, disconnect any wiring harnesses, cables, or rods attached to it, and place it somewhere safe.
3. Disconnect the lock rods and cables
Some actuators come with new cables attached to them; others are bare. It may be necessary to disconnect lock rods and transfer them to the new actuator or latch. There might be door lock cables attached that need to be replaced as well, plus an electrical harness.
4. Remove the door actuator and latch assembly
Unbolt the door latch from the door’s structure from the outside where it meets the striker. Then, pull the door latch out of the door. Be careful not to hit the door glass as it could shatter.
5. Connect the new part
If the actuator you’ve purchased is separate from the latch, switch it over now. Install the new part into the door, making sure it’s tightened well to prevent rattles or the fasteners coming loose. Then, reconnect the wiring harness, the cables and rods, and any other parts inside the door.
Re-install the door panel, replacing any broken clips to prevent an annoying rattle or looseness. Then, connect the battery and test your new door lock actuator’s function.
What Does a Door Lock Actuator Replacement Cost?
On average, a door lock actuator will cost between $125 and $250 for the part alone. Some models can be significantly higher or lower, though. If you need a mechanic to do the job for you, expect them to charge between one and two hours of labor, which could be a couple hundred dollars or so.
Buy your new door lock actuator at AutoZone. With thousands of parts, Trustworthy Advice, and fast options to get your order, there’s no better choice than AutoZone. If the job is too big for you, seek out one of our Preferred Shops to help you do the job.
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