Year 2000 focus locking problem
I've got a mk1 (2000) 1.8 focus. Noticed when its cold only the drivers door unlocks. I have to slam the door shut to make the other doors respond. Recently its got worse and now the remote fob will not lock all doors. You can hear the other 3 doors locking but then unlocking straight away. I then have to lock the car manually by inserting the key. It doesn't seem so bad when the weather is warmer.
What will it be thats failing in the door?