How to Diagnose If Your Car Won’t Start
Now that you have a bit of an idea of why your car won’t start, it’s time to narrow down the causes. With that in mind, we’ve created a step-by-step guide to help you figure out exactly why your car is ticking and won’t start.
#1 – Check the Connections
This isn’t necessarily the most likely issue, but it’s the easiest to rule out. Pop the hood and check the connections on the battery posts. Make sure they’re tight and free of corrosion. Clean the connectors and tighten the connections if necessary. Test again to see if the vehicle starts.
#2 – Test the Battery
Once you’re sure the connections are tight, it’s time to check the battery itself. This step checks both the voltage and cold cranking amps. If you have more than 12.6 volts but not enough cold cranking amps, you can replace the battery. Otherwise, move on to the next step. Note: Most auto parts stores will test your car battery for free. But remember, their goal is to sell you something.
#3 – Charge your battery
Just because your battery doesn’t have enough voltage doesn’t mean you need to replace it. If your battery doesn’t have enough voltage, plug it into a battery charger before even thinking about replacing it.
#4 – Test your battery again
Once your battery is fully charged, test it again. At this point, your battery should hold at least 12.6 volts and provide enough cold cranking amps for your vehicle. If your battery fails in any of the following ways after charging, it’s time to replace it with a new battery.
#5 – Check to see if the car starts
Now that you know your battery has a sufficient charge, check to see if the vehicle starts. If it does, you’re not done yet, but you’ve ruled out a bad starter and can skip this last step.
#6 – Test the generator
If the car starts after charging the battery, check the alternator. If your car’s alternator is defective and you skip this step, it’s only a matter of time before your car won’t start. When you test the generator, it should provide around 14 volts. If it doesn’t, it’s defective and you’ll need to replace it.
#7 – Test the Starter
If you’ve already completed the first six steps in our troubleshooting guide, it’s pretty much guaranteed that you have a problem with your starter motor. Before you replace any parts, though, you should double-check your work by testing the components. Bench test the starter by applying power to the correct terminals and using a small pry bar to make sure the starter has enough power.