Engine won't crank, battery @ 12.8 volts, headlights won't turn on, radio works but after trying to start it radio goes off and then comes back on but not as loud.

With a voltage meter see how many volts are at the starter terminal. If not 12+ volts you have a bad connection. Check connection at the starter solenoid. Does it have 12+volts? Short the solenoid. Does it put voltage to the starter?

Sounds like you have a weak battery, or possibly a bad alternator. The fact that you were able to drive it for 2 days before it died again leads me to believe that it is most likely the battery. You can test the battery by looking at voltage across the terminals when you try to start the car, if it\'s less than 12 volts your battery needs to be replaced. If your battery is more than 5 years old it should be replaced anyway. Good luck, let us know how it goes.

Even though all your other electrical bits are working it could be that your battery doesn't have enough juice to crank the engine. It doesn't take much power to run the radio, lights, etc, but cranking the engine requires the battery to have a very strong charge. If your battery is more than 5 years old, that's very likely the issue. I'd start there. Also, be sure to check the battery terminals and ground for corrosion and clean if necessary. If replacing the battery doesn't solve the problem it could be the starter solenoid or a loose electrical connection somewhere.

kindly pls check the BCM which is located under the left side of the dashboared i hope that will help.

Try this procedure:
Check the battery like this:
Turn on the headlights, then try to start the car.
If the headlights do not dim or go out, then the battery is likely ok.
Check that the battery cable plus post, goes to the starter, Minus post to a good ground, like the engine.
If wiring is ok, then look at the starter solenoid for a good connection, and proper voltage at the starter.
Problem is most likely the Solenoid's bendix gear or starting relay, Have someone bang on the starter while you try to start the car. This usually works by dislodging the bendix gear..
Hope this helps.

Go under the car and see if you have 12 volts at the purple wire to the starter solenoid when the key is held to crank position, the wire may be broken or the starter solenoid is defective.

the clicking that you hear is coming from the starter relay. sounds like your ignition starter switch or ignition lock cylinder is bad.

Make sure the battery cables are tight to the posts. The starter takes alot more current than the headlights and will require more tight of a connection.

Sounds like you have a low voltage problem.Take a volt meter and battery voltage first it should be 12-12.7 volts not running and key off.Then start engine and check the voltage coming out of the alternator it should be 13-14.7 volts.If one of these are not within these specs then replace which everone that is bad.

check ur starter if the car does not crank then thats what it is.