Battery dead

Tiny
CTORRES
  • MEMBER
  • 2009 HYUNDAI GENESIS
  • 4.8L
  • 10,900 MILES
A few days ago wife’s car battery dead. I do not know how to start troubleshooting. But I checked fuses and found one of them hot all time (ROM LP 10a) even car is off. I don’t know if it is normal.
Monday, April 13th, 2020 AT 6:09 PM

3 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,117 POSTS
Hi,

It is normal for many fuses to have power at all times. Now, I do have a few questions. These are things I would start with and do in this order.

1) Are the battery terminals clean and tight?

https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked

2) Check battery voltage / load test.

https://www.2carpros.com/articles/car-battery-load-test

3) If battery is weak, recharge battery and retest (load test).

https://www.2carpros.com/articles/how-to-charge-your-car-battery

4) If battery fails load test, replace the battery. If it passes, move on.

https://www.2carpros.com/articles/how-to-replace-a-car-battery

5) With battery fully charged, start engine and check alternator voltage output (very easy to do).

https://www.2carpros.com/articles/how-to-check-a-car-alternator) If alternator fails, replace alternator.

https://www.2carpros.com/articles/how-to-replace-an-alternator

7) If it passes, conduct a voltage draw test to see if there is a light or component with a constant draw on the battery.

https://www.2carpros.com/articles/car-battery-dead-overnight

8) If there is no evidence of lights staying on or components, then I need you to disconnect the negative battery terminal. Place a multi meter between the terminal on the battery and the negative cable you removed. With everything off, check what the draw is on the battery and let me know what you find.

Normal voltage draws with everything off (approximately 20 minutes after closing the car doors) is .05 millivolts (MV). Once you get above that amount of draw, it can drain the battery over a shortened period of time. Note that is millivolts and not volts. There are 1000 millivolts in 1 volt.

Here are a few links that you may find helpful when testing:

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-check-wiring

_________________________________________

Listen, this could simply be a dead battery. If possible, remove the battery, take it to a parts store and have them load test it to make sure it is good. If it is, then start the tests I supplied.

Also, once we determine what appears to be the issue, I will provide you with the directions to complete the repair. Please feel free to ask questions. If you run into trouble, let me know that as well. I'm here to help.

Take care,
Joe
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Monday, April 13th, 2020 AT 6:26 PM
Tiny
CTORRES
  • MEMBER
  • 58 POSTS
Hello Joe, finally And performed all step you sent to me in step 5 found alternator with fails. Once again thanks so much: Joe, all experts and 2CarPros because in all my issues your help me. I love this web site.
Greetings from Panama City.
PS. I will create a new topics for my Toyota Corolla.
CTORRES.
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Wednesday, April 15th, 2020 AT 11:24 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,117 POSTS
You are very welcome. Come back any time you need help.

Take care,
Joe
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Wednesday, April 15th, 2020 AT 7:06 PM

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