Bongo Fury

My central locking which used to open all doors, now only opens the driver door when I press the remote.
Occasionally (blue moon) all doors will be opened, which leaves me to think either there is dodgy wire somewhere or a linkage is loose. Before I started taking things apart has anyone any advice as to shortcut my fixing this problem please.

very commen fault, broken connection in the loom between the drivers door and pillar, cut it open and you'll see the suspect wire.
Julian

OK, will try that, thanks for the advice.