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Q: Why is the power from my battery not coming through? It was fine yesterday.

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After I put-in a new battery my car would not start when I turned the key, but the lights and radio still worked. I found out it was a faulty security system and all I had to do was reset it. NOW, the power from the battery initially works, but when I try to restart the car after having it on accessories, ALL power from the battery stops. Not even the lights turn on. I unplugged and re-plugged the battery and that seemed to do the trick but not permanently. Is it the battery cables that need replacing?

My car has 110915 miles.
My car has a manual transmission.

A: When you experience a complete failure of p...

When you experience a complete failure of power in the fashion you have described, it is most frequently a bad connection at the battery. Either the terminals or one of the cables has an issue. It’s important to understand that just because a wire is touching a power source, does not mean it is a good connection. It is very common for a connection to exist at a battery post when low current is in use but for that same connection to fail when a higher current is required for the starter. Explaining this phenomenon would be to explain electrical theory and this isn’t the best place for such an explanation.

Some of the things to look for are replacement cable ends, a loose battery connection at the positive or negative posts, and loose or dirty connections at the starter are the typical culprits. Electricity likes clean metal. If it has a surface rust or other forms of corrosion, even if the connection is tight, it can and often will not allow current to flow.

Grab all the connections and pull on them. You should not be able to move them with a reasonable amount of force. If the battery cable ends have a surface film of any sort on them, clean them with sand paper and some battery cleaner from your local auto parts store. If you don’t have any luck with the information I have given you, book an appointment with us. A certified technician can come diagnose the issue with your battery and make the necessary repairs to you car.

Good luck.

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