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Q: Charging system

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The battery was full 12v. I'm turned on engine. But the dash board did not have any light on. Only door open signal and head lights. I measured how many volts there in the battery while the engine run...same 12v. So I guess, not enough electric power to run all functions

My car has 197654 miles.
My car has an automatic transmission.

Hi There, Your battery should have at least 12.6 volts. When the engine is running, this should be anywhere from at least 13.7 to 14.7 volts. If this is not the case, you may have a weak battery or potentially a faulty alternator that is not charging properly. As you may know, the alternator charges the battery while the engine runs by generating amperage and recharging the battery while the engine turns the alternator pulley. The voltage regulator is a unit that regulates the charging of the battery by the alternator and maintaining a certain amperage while the engine runs. When the alternator is not working properly, this may result in the battery quickly losing charge and the car losing all power. You may also notice a whining sound as a result of the bearings inside the alternator begin to fail. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your charging system.

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