Neither. The clicking sound is the noise made by the starter relay. It means that your battery is stone dead! Get someone to give you a boost to start the truck. Once running, if the Charging light comes on, then it means that something is wrong with the charging system, usually the alternator. If the charging light does NOT come on when the engine is running, then charging system is ok, so the culprit is usually a bad battery that does not charge and/or does not hold the charge. In this case you need a new battery. But of course, it could be that the battery is good, but you left your lights on and you drained it completely. So boost the truck, and take a ride at highway speeds for at least 30min to charge the battery, or if you have a battery charger use it to charge your battery overnight. If you can start the engine after the battery is charged, then the battery is good and you just drained it. Hope this helps. Good luck.