adukart all my doors lock when i get up to speed. yours should be doing the same... if im not mistaken that started to be standard on vehicles as a safety measure... our van does it and its a 96. at least im pretty sure it did... granted i haven't been able to drive the rango for the past 4 months...

 

My 2000 Durango used to lock when I got over a certain speed but now it doesn't. Anyone know how to fix that?

 

Check your owners manual, I think there is certin thing you can do to engage that and disengage the auto lock, it would be in there.