I know this has been covered a few times on here, but I recently bought a '98 Disco and the doors won't stay locked. When I press down the driver side lock, all the locks go down for about half a second and then they all come back up. I called a local Rover specialist and they said it was an actuator. They recommended that I open every door and then shut them all firmly just to make sure that it's not an issue with one of them being open. That didn't fix anything. Is there a relatively easy DIY fix for this?

 

It is probably an actuator that is not locking all the way, some times you can clean and lube them, sometimes it is replacement time.

 

Something that might be assumed but you might nor realize because you just bought the truck...ALL the doors MUST be closed before you can lock the doors.
If a door is open then they will lock and then unlock aftrer a second, that is so that you dont lock your keys inside.