My car just clicks when i try to start it, what could be wrong?

You probably have a battery drain from a defect. circuit. Just put a test light between the ground of the battery and the ground cable. If you have a drain problem, the light will go on. Then you remove the fuses one by one until the light goes out to isolate the circuit. A electrical wiring diagram will be appreciated. I would say it is the installers fault and that the alternator is probably working fine, but the alternator is either hooked up wrong or has a broke wiring harness or the belt is under driven or this is the wrong alternator for your vehicle. or the best answer is you have a short somewhere causing the charge from the alternator to not reach the battery. In other words the pathway is broken. There can only be a few answers to this question. Something is broken/loose(wiring) /installed wrong/or the wrong part. Try the z net from autozone. It will give step by step instructions. You need to include further information of the vehicle(year/make/model/size engine/ if you want specific informationPull the pos strap off of the battery when the car is running, if it dies and you know that the alternator is good you could have a short. That could be what is killing your batteries.

Is your car killing batteries overnight? Could have a short somewhere else and that short just put more strain on your alternator.one way to see is to start car with nothing on in the car an remove hot lead from battery car should stay running if it do turn head lights on car should die Resistance in the wiring due to corrosion or poor ground. Sometimes theres a regulator that controls the voltage and amps within the alternator that is defective

Unfortunately there is no real easy way to find the issue here. Firstly, is it taking charge? The first and easiest option is to replace the battery. First, just have someone put a meter on the battery which will indicate if the battery is no good. At that point, if it is looking okay, we would put our sights on the alternator. To see, with a new battery or one charged, start and run the car. If it still dies out so quickly you will probably have it brought to a mechanic.

Oh, and FIRST step is getting that battery exchanged. That is most important!!

When my cutlass did this I first replaced the battery then alternator but it still kept getting dead batteries. The fix was it needed a new starter.