if you quickly lift the handle when it unlocks for that split second you can usually get in .if not open the tail gate and go in over back seat and unlock door from inside .take the fuse out of cenral locking to stop it working and they usually work manually.as for fixing it you will need to find which unit is causing it or it may be a wire i have left them off for a day or two and when they have dried out the problems gone l think by the way you discribe it a ford dealer my be the answer
bob, March 2012