Assuming the door lock is hard to unlock with a key because it is dirty or gunked up inside and not damaged your best bet is to use a dry graphite.
Key not working in door lock.
Door locks are complex mechanisms with lots of tiny moving parts and as such can malfunction on occasion.
After a long day at work the last thing you want is to come home put your key in the lock and find that it won t turn.
If you are able to lock and unlock the doors with the physical key then the locks are probably fine mechanically.
Here we look at repairs for locksets and knobs.
Dry powdered graphite will not.
However there could still be an electrical problem.
For other types of problems with door knobs and locks please see repairing door knobs hardware.
You may be able to take care of the problem yourself or you may need to call a locksmith for help.
Don t use a wet lubricant that gum up locks.
The most common type of car key used to be the traditional car key which was mostly just a physical key that was used to engage your car door locks and work in conjunction with your ignition.
Door key does not work.
Chances are if you own a vehicle that was manufactured before 1995 then your car keys are the more traditional kind.
Flip the key and open the door.
A key that doesn t turn in the lock could have several causes.
Many door knob and lockset problems can be corrected before they become so serious that the lockset does not work at all.
You can rule part of this out by locking and unlocking all of the doors via the physical primary control inside the vehicle which would indicate that the electronics are fine.
See below for taking apart your door lock and getting it to work like new.
Spray the lock with lubricant to remove dirt and dust.
A dry graphite lubricant will lubricate the inside of the lock making it easier to unlock.
Here we look at how to fix problems with a key operating a door lock.