If you jump into the car, turn the key and nothing happens, you might be wondering whether it's a faulty alternator, battery or starter. The three major electrical components of the car work together in tandem to provide the right amount of power to kickstart your engine. As they work closely together, it can sometimes be difficult to determine which part is faulty.
What do you need to know about determining the true problem?
It's a good idea to always start with the battery, as this is frequently the part that fails first. It also happens to be the lowest cost component when it comes to replacement. Typically, a car battery should last you for a few years. Understand that it is just a receptacle and is not designed to store power for any period of time. It is designed to be constantly recharged by the alternator while you're driving along. What are the signs of a battery problem?
If you notice a low, humming sound as you are attempting to start the car, this could be a sign of the battery's death knell. If a friendly neighbour has helped you to jumpstart the car and get the engine running, only to find that the car won't start again if it stalls, this indicates that the battery is the issue. In this case, the battery is unable to hold the charge once the alternator has been shut off.
However, if you've noticed a more aggressive, growling sound, this is an indicator that the alternator may be on its way out. Also, this can be accompanied by a burning smell as the alternator overheats. In this case, when your friendly neighbour has helped jumpstart the car, you may notice that the engine dies right away after you've disconnected the jumper cables. When this happens it indicates that the alternator needs to be repaired or replaced. If you'd noticed that your headlights appeared to be alternating between bright and dim previously, this was also a warning sign that your alternator was failing.
Signs that your starter has failed include a clicking sound whenever you try to start the car or the fact that all the dash lights appeared to be functioning correctly but the car won't start. When you do try and jumpstart the engine, it won't turn over at all.
A professional mechanic can help you to diagnose the issue once and for all and will be able to help you with starter or alternator repairs.