Hi my central locking is not working, when the sliding door is closed the lock is really stiff, it can't be locked with the key. When the door is open it moves freely. When the lock button is pressed you can hear a click in the side door. This problem is also causing my battery to discharge when it is sitting. Can anyone help with ideas please?

Had a similar problem with my L300 Starwagon. Turned out to be the central locking switch control was holding the locks on. Ran my battery flat a few times before I found it. Replaced the switch and it was sorted.

Thanks. Is there a way to test the switch and how would you know which switch it is? Sorry I haven't had much to do with electrics or central locking.

Remove the switch on the dash (lock/unlock) and unplug it. Then see if you're battery loses its charge.

My switch is on the arm rest and is joined to a circuit board with the electric windows, with only one plug for the lot.

Try disconnecting it and see what happens . Check to see if the door lock works manually. If it does then chances are this is the source of the problem.

Thanks for that, I have done that and I'm leaving it overnight. I should know in the morning. I also tried the lock and it was easier to use with it disconnected. So heres hoping the problem will be solved. I have been told by so many 'professionals' the problem was in the batteries or the alternator, they wouldn't listen to my theories, probably cause I'm a girl. It's cheaper to do it myself anyway.
Thanks again.