right central locking was working fine the recently started to lock itself when left or driving, battery was nearly flat and last night the alarm went off got back ferom work to find car unlocked and windows down a bit, jumped the car and starts fine but now cant lock the car if i manually lock it i can use the key to open as normal just seem to have lost the lock function any ideas? ( no key fob only key operated 1998 1.8t )