Hi, Claire.
I can't answer your question at the moment, but I have the same problem, and am looking for a solution. The problem has been intermittent for a while, i.e. it would have a spate of not locking, then would be OK again for a while, sometimes for months! Now it seems to have failed permanently. I suspect a broken wire, possibly in the wiring from the driver's door to the front pillar, because that is subjected to a lot of flexing. However, in the absence of a wiring diagram, I'm a bit stuck. Mine's a 2002 Xsara Estate, for which there isn't a Haynes manual, but there is a manual for 1977 to Sep 2000, so that might cover yours!
If anybody can help either of us, it would be much appreciated!
Peter
February 2008
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix cars.