Hi there, 1986 560SEL, my door locks act like the following:


Use the key in the trunk to unlock and lock everything, all the other doors unlock and lock fine except the driver's door stays locked.

Use the key in the passenger door to unlock and lock everything, all the other doors unlock and lock fine except the driver's door stays locked.

Use an aftermarket keyless entry (which was installed for years and worked for years and still does), it unlocks and locks the trunk and all other doors except the driver's door stays locked.

Use the key in the driver's door to unlock and lock everything, all the other doors unlock and lock fine as does the driver's door.


What say you?

Sounds like you have a bad actuator in the driver's side door. Easy replacement.

Just be careful taking off the door card; it has plastic L shaped retainers in the door card that will break. You must slide the door card up and then pull it off the door frame - otherwise you risk breaking the plastic retainers.

Think I paid between $25-50 for actuators maybe five to ten years ago when I replaced two on my 300 SD.