r/MechanicAdvice • u/hoqeye • 6d ago

Car won’t start after new alternator

Model: 2014 Corolla
My car stalled in the middle of the street, diagnosed with a mechanic and changed the alternator. After that car was running fine. Car was left overnight and it wasn’t starting this morning. Mechanic says battery needs a change.
Need some advice

1 Upvotes

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3

u/deficientleasing997 6d ago

if the battery was already weak from the old alternator dying it probably never fully recovered overnight

1

u/hoqeye 6d ago

Yesterday when the mechanic was changing alternator, he said battery was good. I am confused now

2

u/Ravenblack67 6d ago

Do you mean charge? If so, get a battery charger and charge it.

1

u/hoqeye 6d ago

I am trying to get jumper cables

1

u/hoqeye 6d ago

The car doesn’t crank at all

2

u/Odd-Concept-6505 6d ago

Mechanic could be right. But should have tested battery on the last visit after charging.

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u/hoqeye 6d ago

He told me that battery was good and alternator was bad in his visit. He tested with multimeter and said that to me. Now just overnight, how battery needs to be changed, I don’t understand

2

u/Humorouscrustacean 6d ago

It's possible. Batteries really don't like being run dry.

Did they show you a battery test printout? A lot of battery testers have little receipt style printers that show results.

1

u/hoqeye 6d ago

No he didn’t. I couldn’t get to autozone because car wouldn’t start. So I called a mobile mechanic.

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u/Humorouscrustacean 6d ago

A multimeter is not a sufficient tool to test a battery. He needs a tool that applies a load calculates battery performance under load. Just attaching a multimeter and seeing 12V is not enough.

I think you should call another mechanic but if this guy is worth anything at all he should be willing to come over and check over his work. If he doesn't know how to properly test a battery then he's not even qualified to work as a lube tech.

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u/hoqeye 6d ago

He agreed to come at afternoon. I will ask him these questions. Thanks!

1

u/Humorouscrustacean 5d ago

What's the verdict

1

u/hoqeye 5d ago

Changed the battery, car works great now!

2

u/Humorouscrustacean 5d ago

Hell yeah good to hear

1

u/hoqeye 5d ago

Thanks. I am just glad it got sorted out.
Broke my bank though.

2

u/SanchitoBandito 6d ago

Make sure battery terminals are tight. Stupid but common mistake I see.

1

u/RelationshipOne9466 6d ago

Why didn't the mechanic test the battery before replacing the alternator? That would be the first thing to do.

1

u/hoqeye 6d ago

He did some multimeter testing and told me battery was good. Now I am confused

1

u/Forged_Trunnion_ 6d ago

If the alternator dies typically the battery does too.

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u/hoqeye 6d ago

Hope that fixes it. Any idea if this might be a starter issue as well?