How can you tell if your car has a battery or alternator problem?
It can be hard to determine if you’re dealing with a battery or an alternator problem. Here’s how to know which one is the culprit.
What does a car battery and alternator do?
What the Battery & Alternator Do. An auto battery supplies a big electric charge that travels through the starting system and turns some gears to start the car. Once the car is running, the alternator sends current back to recharge the battery as you drive.
Why does my alternator not work when I jump start my car?
Improperly jump starting a car As with the car battery, switching jump cables can cause alternator problems. Namely, if you switch the plus and minus cables (from the “donor” car to yours) you can again damage the diode rectifier. Even worse, you can damage the “donor” car as well.
What should I do if my battery won’t start?
If you run into this type of problem a cheap voltmeter can become your best friend. If you have no starting current, check the “open circuit” (ground cable removed) from the battery and the voltage checked at the battery’s terminals. It will almost always be normal. Reconnect the ground cable and re-check the voltage.
Can a bad alternator cause a battery to fail?
Yes, you still have a problem when you have a new battery and a bad alternator because a bad alternator can destroy a working battery when it charges it using too much voltage. Higher than recommended voltages lead to premature cell failure within the battery.
How can I tell if my alternator is draining my battery?
Another way to tell if an alternator is draining your battery is by running your car and unplugging the battery’s positive connection. If the car immediately stops running, your alternator has malfunctioned because it should depend on the alternator and not the battery after starting. Another simple way is to test your interior lights.
Is it time to replace your alternator or battery?
If so, it’s time to replace it. Some may recommend running the engine with the negative battery cable disconnected to test the alternator. However, this is not a good idea because it could damage the electrical system of your vehicle and cause greater problems. Fixing your battery or alternator can be an expensive repair.
How does an alternator start and run an engine?
Starting and running an engine, in its simplest form, is a three-step process. First, the battery delivers a jolt of electricity to the starter. This starts the engine running, which puts the alternator into action. Finally, the alternator completes this cycle by charging the battery.