99 Q45 Stuck/Frozen Interior Right Rear Door Lock

[Mustang51D]

The door lock on the right rear interior passenger door is "frozen" or "stuck" in the unlocked position. All other three doors operate fine manually and electronically. However, on this one, I cannot even push the tab closed with my thumb. The power window operates normally. What could cause this? Thanks.

[RustyBucket]

If you can't even move the lock tab with your thumb then the problem is probably mechanical in nature and not related to the power locks.

Something in the mechanism is probably stuck, loose or broken. I'd say take apart the door and figure out what's stuck or not moving like it should. You could also try lubricating the lock and latch mechanism externally before you start any disassembly.

[Mustang51D]

Thank You! I will take your advice and give it a try.

[Mustang51D]

Thanks Rustybucket - I took your advice and did not remove the door panel immediately, but first sprayed some Aero Kroil (a stronger type of WD-40) spray on the latch mechanism. over 3-4 days the lock became unfrozen little by little and now works perfectly.
John P.