It's not easy to troubleshoot your car problems but it is a good idea to know what is wrong with your car before bringing it in to a mechanic. Plus, you can save money if you can repair the problem yourself.
Turn your headlights on to see how bright the lights are, or if the lights even come on. This is a good test to see if your battery is fully charged. If your lights come on and seem of normal brightness, the battery is not an issue.
Check your battery with a voltmeter by putting it across the terminals. If the battery is fully charged it will read, 12.5 volts and a dead battery will read less than 11.8 volts.
Watch for dimming of the idiot lights when you start the car. If they dim, then your ignition switch is working properly.
Find the solenoid and look at the back of it for two big post electrical connectors. Put your transmission in neutral and your parking brake on.
Take the rubber handle of a pair of insulated pliers, and drag them across the two big post terminals. You will see sparks, but hold the tool in place until you get a good connection. This will connect the battery to the starter motor, without using the solenoid. The starter motor should spin but will not start the engine. If it doesn't spin or it sounds bad, you will have to rebuild it.
Return the transmission to neutral and put the parking brake on. Behind the solenoid, you will again see the two post terminals. Look for a heavy braided wire connected to the solenoid and the starter motor. Touch the positive lead of your voltmeter to the braided wire and ground the negative lead. Ask someone to turn the key to start. If the measurement is not "12v" on the voltmeter, the solenoid is not activating and it is not sending power to the starter, your solenoid is defective. Remove the solenoid and have it rebuilt.
