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Q: Charging system failure???????

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About a month ago the battery light would come on periodically. Then it stopped so I let it go. Well on my way to work about thirty minutes away the battery light came on I could pull over and turn it off and restart it the battery light would be off . Just driving a few miles around town it never came on. Well another time on way to work the light came on and even when I stopped the car and turned the engine off when turned it back on the battery light was still on I made it almost home and it died and wouldn't restart. Went back cpl hours later and it started we didn't jump-start it. We bought a new battery about a month ago. the alternator changed about eight months ago. Everything seems tight the belts not loose but what is considered too loose anyway? I don't really know. Anways I just spent four hundred at a mechanic changing wheel bearings so I can't afford another mechanic what can I check ?

My car has 137863 miles.
My car has an automatic transmission.

It depends on the tools you have. If you have a voltmeter, then you can check the voltage at the battery posts when the engine is running. When you do this, make sure that you turn on the normal accessories that you like to run, such as the A/C, stereo, lights, and so on.

The the voltage should be close to or above 13 volts. If the voltage is below 12.5 then you may have a problem with the charging system and would need to have the system checked by a mechanic who would have the special tools to conduct an in-depth inspection of the alternator, computer, and battery.

Also the battery sensor could be malfunctioning and should be looked at. If your car is dying from a low charge then you may need to have it replaced. If it is the alternator or battery then you may have a parts warranty that may cover the replacement or the parts but not the labor.

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