Welcome to 2CarPros.
If the battery is going dead when the car sits, it sounds like what is called a parasitic draw. Take a look through this link. It discusses the most common causes for this type of issue.
https://www.2carpros.com/articles/car-battery-dead-overnight
I need you to also confirm that the alternator is doing its job. Here is a link that explains how to test an alternator:
https://www.2carpros.com/articles/how-to-check-a-car-alternator
You will need a volt or multi meter to test the alternator. If you find that it isn't replacing the charge in the battery, let me know.
Here is a link that shows how to do basic wire testing and use a volt meter:
https://www.2carpros.com/articles/how-to-check-wiring
https://www.2carpros.com/articles/how-to-use-a-voltmeter
Next, confirm the alt s fuse is good in the under hood fuse box. See pictures 1 and 2. Picture 1 shows the entire fuse box and in picture 2 I circled the fuse. Here are a few links you may find helpful:
https://www.2carpros.com/articles/how-a-car-fuse-works
https://www.2carpros.com/articles/how-to-check-a-car-fuse
https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester
I also need you to test for power for the main alternator fuse in the same box. If you look at picture 3, it shows power goes through a fusible link. It looks like a wire, but it functions as a fuse. Check that fuse as well as you need to confirm that link hasn't failed. You should have power at the fuse if the link is good.
Either we have something drawing power all the time or the alternator isn't able to do its job. There are specific wires called fusible links that can fail and not allow the alt to charge the battery, so let me know the results of the above tests and I will direct you as to what needs done next.
Let me know if that helps or if you have other questions.
Take care,
Joe
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Wednesday, June 19th, 2019 AT 10:50 PM