Why does the alternator light come on when you start the car?

Why does the alternator light come on when you start the car?

When you start the engine, the car will check to make sure the alternator is outputting the correct voltage. This warning light will shut off after a few seconds if the computer has determined that the alternator is functional. When the light stays on, it indicates that the computer has detected an issue with the charging system.

What are the symptoms of a bad alternator in a Nissan Sentra?

If your Sentra’s alternator starts to have bearings that fail, it’ll begin to make some very obnoxious noises. If the serpentine belt has gone bad, it can make some noises too, but it won’t sound metallic like the bearings going bad would. Dimming headlights are one of the most common signs of a bad alternator in the Nissan Sentra.

What does the alternator warning light ( battery warning light ) mean?

What Does the Alternator Warning Light (Battery Warning Light) Mean? The alternator warning light means there is an issue with powering the battery. This could be due to the alternator becoming worn out.

What should the resistance be for an alternator?

If all this checks out then I suspect you have a wiring issue. I would perform either a voltage drop or resistance measurement of each of the wires from the PCM to the alternator. Also, through the fusible link from the battery to the alternator. You should have less then a half ohm of resistance.

If your Sentra’s alternator starts to have bearings that fail, it’ll begin to make some very obnoxious noises. If the serpentine belt has gone bad, it can make some noises too, but it won’t sound metallic like the bearings going bad would. Dimming headlights are one of the most common signs of a bad alternator in the Nissan Sentra.

Why does my alternator warning light keep coming on?

When the light stays on, it indicates that the computer has detected an issue with the charging system. If this light illuminates, try to use only necessary accessories like windshield wipers or headlights so as to avoid excessively draining out the battery.

Can a bad alternator cause a car to not start?

Once this battery reserve hits a certain level, the vehicle will begin to run erratically and will no longer start when the key is turned. Often, the battery light will come on, the alternator gets replaced, and then a few days later the vehicle dies.

What does it mean when your alternator stops charging the battery?

Indicator Light On. Usually, the first sign that your charging system is in trouble is a “battery,” “ALT,” or “CHARGE” warning light illuminating on your instrument panel while driving. It means that for some reason, the alternator has stopped charging the battery and your car is running on battery power.