How to diagnose a dead battery

 In Neal's How-To's

How to diagnose a dead battery from another car issue:

At Neal’s Garage, we are prepared to help you with all of your car needs. Last week, I wrote about how to jump your car. However, our customers have been asking how to diagnose a dead battery from something more serious. Jumping a car battery can be relatively easy, but you may have to bring your vehicle to Neal’s for another issue. This week, we will tell you how to diagnose a dead car battery so that you can know when you jump your car.

Most cars have a dome light on the side of the door. When you open your door, this light may be noticeably lower than normal or even completely off. If you notice one of these two differences, put your keys in the ignition with the door open, and listen for a door chime.

If you hear a door chime, proceed to start your car normally; if your car will not start, proceed to the next step.

If you do not hear a door chime and/or your dome lights are dimmer than usual (or off), and your car starts normally, this is a sign of a faulty door switch or that a fuse or lightbulb is out.

If you turn the ignition key and nothing happens, try to turn on your headlights and/or your radio.

If your headlights and radio won’t turn on, and your car also won’t start, then the problem is usually a dead battery.
Alternate causes to the radio and/or headlights not working other than a dead battery could be a blown main fuse, corroded battery connections, or other wiring issues.

If you do not feel anything when you turn the key or hear the starter motor, this could be a sign of a dead battery, and you should try to jump your car.

If this does not resolve your problem, it could have another cause like a faulty starter, ignition switch, or fusible link.

If you hear a starter motor when you turn the ignition key, but the engine doesn’t start, move to one of the next two steps:

If the engine does not start but the starter cranks at a normal speed, then you have a bad starter motor, or a lack of fuel or spark.

In this case, jumping your car will not help. Unless this problem is because you are low on gas, it is best to let a professional diagnose the issue.

If the engine does not start and the starter motor sounds labored or cranks slowly, OR if it cranks and then stops altogether, then it is much more likely a battery issue. In some cases, it may still be a bad starter motor or the starter may be attempting to draw more current than the battery can supply.

If you notice that your car won’t start in the morning without a jump, but it starts fine later in the day, there may be an underlying cause that is killing your battery overnight.

This could be caused by a parasitic drain, which means your battery may need to be replaced. However, the only way to determine if you need a replacement is to determine the source of the drain.

The ability of a battery to provide on-demand-current to a starter motor diminishes when it is cold outside. This means that you may need a battery replacement as well. If you frequently have this problem, Neal’s can help you choose a new battery with a higher cold-cranking amps rating.

I hope I was able to answer all of your questions about understanding the differences between a dead battery and another car issue. Remember, if you are frequently having problems with your car or battery – bring it to Neal’s to see a qualified professional and have your problem diagnosed today! We are conveniently located downtown near Ninth Street in Durham, NC.

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