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Alternaor Question, 1997 Jeep Grand Cherokee

I have a 1997 Jeep Grand Cherokee Laredo that needs a new alternator. There are two alternator types available, a 90amp and a 120amp. I think my current alternator is a 90amp and my question is, would it hurt the car to put the 120amp alternator in?

No, it would not hurt, but at some stage you may also want a much larger battery.

Typically in cars the larger alternator is used on commercial vehicles, such as taxis and police cruisers, and cars with a lot of accessories.

My cars have always had HD batteries and alternators. If you are towing a trailer and camping a larger alternator and battery is a “must have”.

No, but it probably won’t do any good, either, so why spend the extra money?

Thanks for the replies. The 120amp is only $17 more so that got me to wondering. I don’t to very much towing but we do camp quite a bit so I’ll mull it over. Thanks again and Merry Christmas!

No possible way it would ever hurt anything. It would help things considerably: promotes battery life, headlights wont get dim at low idle, etc. A friendly word of advice, buy the alternator at Napa and get the lifetime warranty on it. I kid you not, the 120amp alternator on my Explorer is ten years old.

You might get the parts store to put both alternators on the counter and compare them. They may not be interchangeable. And unless you have some added accessories or your driving involves long periods of idleing the added amps will never be used. And a larger battery will actually afford a smaller alternator.