Check to make sure the pins that carry electricity to the lock are lining up
with the reciever plate.  Had the same problem with the lock on my Carat and
that is what it was.  Then you will just have to loosen the bolts on the
bottom slider and adjust the door up or down a little until your pins are
hitting the plate they way they should.
Let me know what you find.
Ken Wilford
John 3:16