Take your car to a garage and get them to perform a load test on the battery, if the meter needle falls rapidly and does not hold its mark then you have a dud battery.
Always make sure the cells to a battery are always checked and topped up with distilled water available from most motor accessory shops.
If it is not the battery and you get a clicking noise this is the solonoid doing its jopb on top of the starter motor. If you are able to get a long heavy object and tap the side of the starter motor only (Dont hit the solonoid) if the starter then starts the engine this is due to dirt getting between the brushes which means the starter motor will have to be repaired or replaced usually the latter. good luck.
Switch headlights on and turn key, if the headlights dim to nearly going out suspect the starter motor.In any event get a load test done.
Carlito Corway, February 2007
