Defective car door locks may not be as serious or annoying as major engine issues, but any inoperative automotive components deserve the same attention. Locks are there for a reason. They’re a crucial safety and security part, deterring theft and unwanted tampering, and keeping all occupants safe when driving. Most cars today have automatic locking mechanisms to lock and unlock the car remotely using a key fob. This provides for more safety and convenience, faster operation, and generally lower maintenance than older manual lock systems. A key component here is the door lock actuator.
Basics of Power Car Door Locks
Car door locks aren’t overly complicated but still consist of several parts that work in unison. This includes handles in and outside the car, the locking mechanism consisting of latches and door lock actuators, lock buttons on the doors, and keys or fobs. On power door locks, the actuator is the part that moves latches up or down to lock or unlock the door.
This is a relatively simple process. Inside the actuator, you’ll find a small electric motor that turns a set of interconnected gears. The final gear is a rack-and-pinion gearset, connected to the actuator rod and this converts the rotational motion of the motor to a linear motion that moves the rod up and down.
When the actuator moves the latch up, it engages the outer door latch with the door-locking mechanism. With the latch down, the locking mech is disconnected, and doors can be locked by using buttons on the inside or with a key from the outside. A centrifugal clutch allows door locks to be mechanically opened and closed when the motor and actuator fail.
Can Lock Actuators Break?
Power door locks based around actuators should last over 100 thousand miles before general wear and tear starts creeping in. Quite a few things can wrong. Motors, gears and wiring generally last but may be susceptible to faults in the car’s electrical system, such as dead batteries. More worrying are weather and temperature extremes, as well as moisture that can cause corrosion and rust buildup until actuators are not functional.
The same applies to vehicle damage sustained in accidents or intentional tampering, with mechanical faults to linkages the prime reasons why doors won’t lock or stay locked. Since door lock actuators and mechanisms fit in the door panelling, even minor exterior damage can lead to difficulties. Lastly, the use of non-standard parts (either from the factory or as a replacement in cars involved in accidents) will lead to premature lock failure.
Signs of Defective Actuators
Power door locks are more of a convenience that we’ve accepted, rather than being an absolute necessity. Stuck doors, however, can be a safety hazard. With most cars now having an auto-lock feature when in motion, passenger and driver safety can be compromised because of faulty locks. The same can be said if doors can’t be opened and unlocked from the inside during accidents or emergencies. With that said, here are signs that point to locking mechanisms and actuators that are nearing their due dates.
- Irregular operation – if your doors fail to consistently lock or unlock, there’s a high likelihood of damage to the actuator or the latches. When door locks work on an on/off basis or struggle, time to consider replacement parts.
- Noises – Faulty actuator motors, damaged gearing, bent rods and stuck latches can produce grinding or whining noises when trying to lock or unlock the door.
- Locks with a mind of their own – problematic are locks that start to lock or unlock doors by themselves. This can also mean a wider problem with the car electrics.
- Painfully slow operation – actuators can struggle and take their time. Usually, the whole procedure is instantaneous, but faulty actuators result in doors that take several seconds or even minutes after pressing the fob or switch to lock or unlock, or not at all.
Finding Replacement Parts
If you notice one or a combination of the signs above, time to consider a working replacement. Automotive door lock actuators are inexpensive to buy, and quick to replace, with low labor costs. Actuators can be had in different types, depending on whether they’re used on doors or liftgates, and in sliding doors or powered liftgates. As always, consider your VIN number to ensure vehicle compatibility, and that the doors and tailgate lock and unlock when required.
OEM parts are recommended by car makers as they’re simple drop-in types with no additional work required. However, there are also universal actuators that should fit a number of car models, and these are often (but not always) easier on the pocket. The good news for older makes using mechanical locks, is that mechs and actuators can be retrofitted and installed if you want the convenience and speed of power locking. Needless to say, you should get the work done by a pro to avoid ill fitment and an actuator that doesn’t work or affect related car systems.
Can You Drive with Faulty Lock Actuators?
These parts won’t impact engine performance, but you will need to manually operate one or all locks. Driving with faulty locks is possible, but you lose out on the convenience, safety and security. And not rarely can one automotive issue extend to other car parts and systems. For instance, electrical issues with motors or the wiring can cause blown fuses or switchgear, or in severe cases short circuits and damage to more expensive parts, like batteries and alternators. Many vehicle safety systems are also tied with working locks (alarms and keyless locking for instance), so these may be disabled if the car’s ECU senses a fault.
Summing Up
Basic vehicle components like lock actuators are commonplace in all new cars today. Their purpose is to quickly and securely lock and unlock the doors or trunk, and do this consistently and without issue. If you sense that actuators or locking mechanisms work erratically, slowly or not at all, there are easy-to-find vehicle-specific parts to fix the problem. For the best fit and actuators that work as advertised, shop OEM parts or OEM replacements from well-stocked automotive parts retailers.
