In order to troubleshoot a no-start problem, you need to start at the beginning of the line, the battery, and work your way back. Some tests for a no-start problem are simple, others are a pain in the neck and a technical nightmare. Nonetheless, you need to figure out why the car won't start, so we'll try to help. If your key won't turn in the ignition, try this fix.
Electrical No-Start Problems
- Check Your Fuses: Few cars have a fuse associated with the starting system, but before you go monkeying around with everything, check your fuses to be sure it's not that simple.
- Battery Corrosion: Over time your battery connections can become dirty, or corroded. This corrosion breaks the connection your battery has with the rest of the car, and it won't start. Try cleaning your battery posts and try to start the car again.
- Dead Battery: The most common reason your car won't start is a dead battery. If you have a battery tester that can measure cranking amps, test your battery to see if it's weak. If you can't test it yourself, you can test the battery indirectly by jump-starting the car. If it starts right away, your problem is most likely a dead battery. Replace the battery, and clean the battery connections to ensure good contact.
- Bad Igntion Switch: If your battery checks out, but the starter is still silent, it may be a faulty ignition switch. Turn the key to the on position (not all the way to start). If the red warning lights on your dash don't light up (and your battery connections are clean), the ignition switch is bad. If they do light up, turn the key to the start position. The dash warning lights should turn off at this key position (most cars). If you're not sure, turn on the headlights. When you try to start the car, the lights should either dim (a lot) or turn off completely. If they do, your ignition switch should be ok. If not, the switch will need replacement.
- Bad Starter Connection: Corrosion can not only keep your battery from connecting, it can affect any electrical component, especially the ones exposed to the elements like the starter. If you have a helper, you can test the connection by holding a circuit tester lead on the wire that engages the starter. This is the smaller of the two wires connected to the starter. Be sure no part of your body is near the moving parts of the engine - it could still start at any time! Have a friend turn the key and check the current. If you're getting current to the starter but it ain't spinning, it needs replacement.
If your starter spins freely when you turn the key, the problem lies elsewhere. Now you begin to check the other systems that could keep it from firing up.