1) Check to see that your battery is connected properly, maybe the cables are loose.
2) Check the battery posts for "white dust" which is corrosion. If so, brush off with something.
3) Check your battery wires. They are the rubber cables that connect into your engine block. They might be old and the connector tips might be worn out. Just pull one out and see, they pull out like a suction cup. Might be time to go and buy another $20 pair. If you see fraying or bent pieces, then replace. Be sure to tell Auto Zone the make and model of your car and if it is a 4-cylinder (if there are 4 rubber wires, then it is a 4-cylinder).
4) Take your car by Auto Zone and they will bring out a battery charge tester for free. They'll eliminate or confirm that it is your battery to blame.
5) Have someone check your starter (where the 4 rubber cables come out of). It might need replacing, might be about $150 or so.
6) After all this, if there is still a problem, then it might be an electrical problem with your car. Have someone check the fuses underneath the dashboard to see if they are loose or broken. Otherwise it might be a bad wire. More likely the older the car and if all else fails.
