What should battery gauge read

Click to see full answer. Also question is, what should my alternator gauge read? The voltage should read a minimum of 13 volts. Stress test the alternator - Place a load on the alternator by turning on the headlights, the radio and the air conditioning.

The voltage should remain high with these circuits on. Additionally, why does my battery gauge go up and down? Before condemning the alternator though, one other thing that can cause the battery gauge to go up and down is if the wires aren't connected well or are corroded. Clean off any corrosion and tighten down any loose wires before replacing the alternator unless you know for sure it is bad. It tells you your battery or your altenator. It shows you the voltage at the battery terminals.

If the engine is off, this will be the battery voltage, if the engine is on this will be the altenator voltage which is higher than the battery voltage in order for it to charge the battery.

Test the alternator for magnetism. Use a metal screwdriver and place the metal end very near the bolt on the alternator pulley. It's on the front of the alternator and the alternator belt goes round the pulley. The end of the screwdriver is not drawn towards the bolt as there isn't any electrical magnetism.

Readings of 14 to This is typical of a properly operating charging system. If the voltage reading drops below TOM: When the battery is low, the alternator will produce a little more than 14 volts. RAY: When the battery is charged up, only about 12 volts will be produced.

TOM: If your voltmeter occasionally reads less than 12 volts, that's probably nothing to be alarmed about. If you have the lights on, the windshield wipers going and the air conditioner on, and you're sitting at idle, a temporary drop below 12 may just mean that you're using a lot more electricity than the alternator can produce at that low speed.

If you discover that the lights are a little dim, then that could be an indication the lights are being powered primarily by the battery. In such a case, this means there is little or no charge being created by the alternator. With your headlights on, try revving the engine. If your lights shine brighter during the rev, it could mean that your alternator is producing some current, but not enough at idle to maintain a sufficiently charged battery.

If your interior lights are gradually dimming as the car is running, your alternator is likely to blame. If you remember hearing a slight growling sound coming from your vehicle before your things took a turn for the worse, that may be a clue that alternator is deteriorating.

Here are a couple of ways you can test your battery voltage yourself. An exception for many may be the voltmeter or ammeter, both of which are used to display the state of your car battery. Once you understand exactly what they measure, you can also read your car's battery gauges.

Look at the voltmeter on the dashboard of your vehicle. Cars operate on a volt electrical system. A fully charged battery should read about Look at the voltmeter while the engine is running.