More likely a dud battery, or a duff alternator.The clicking sound is because there is not enough battery power to start the engine, but enough to activate the starter solenoid,which is clicking. Although the lights, etc,. may light up, they take relatively a small amount of current compared with a starter motor. There may be a faulty or corroded battery terminal connection, or a slack drive belt, or even a dud starter motor !
davidj, November 2011
