the drivers side door of my ST24 doesnt lock if i use the keyfob, or lock using the other doors, it does lock all doors if lock from the drivers door or use the key in the drivers door. Does this sound like the central locking motor? as i have just seen summit on ebay called an "Infared sensor" which they say is also stops doors locking properly if it goes, haynes doesnt list this thing, so am watching a locking motor and this sensor but wanna know which to get to be honest lol, or could it be summit else like a soleniond