105A or 145A alternator?

2003 CHEVROLET AVALANCHE

145,000 MILES • 5.3L • V8 • 4WD • AUTOMATIC

BRENTULRICH88

MEMBER
38 POSTS

Hello,

I need to replace my alternator, however, it doesn’t say on bad one what amperage it is. Will it hurt if it’s a 105 and I just install a 145? Please advise, and if it does need to be that specific amp where would I be able to locate it.

Thanks

Sep 17, 2021 at 5:36 AM

SQM

✓ASE Certified Mechanic
6,383 POSTS

Hello,

You want to make sure that the replacement alternator has the same output as the one in your vehicle. So if you have a 105A that is what you will need to install.

The best way to know what came in your vehicle from the factory is to call the dealer and provide them with your VIN. They can tell you what is the part number and the Amp rating that was installed from the factory.

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

Please let me know of any questions.
Thank you.

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Sep 17, 2021 at 10:25 AM

BRENTULRICH88

MEMBER
38 POSTS

So I ended up taking bad one to parts store and they put a 105 and 145A side by side and it was clearly a 105. 145 was way bigger, lol.

Sep 17, 2021 at 10:27 AM

SQM

✓ASE Certified Mechanic
6,383 POSTS

Glad you got it figured out. The 145 does have heavier gauge components so it is bigger.

Sep 17, 2021 at 10:34 AM