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alternator amp output


LeBronCo

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Looking to replace the alternator on my 86 B2 2.9L. I'm getting conflicting info regarding how many amps should the alternator put out. Anywhere from 40 amps to 130. I'd like to upgrade a bit from stock. Any suggestions?
 


Uncle Gump

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Alternators... much like batteries... the rule is usually the bigger the better.

It never hurts to have the potential.
 

LeBronCo

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OK Uncle G, I've read the shop manual cover to cover and no mention of alternator output. What is the factory set up?
Nelson
 

Uncle Gump

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I don't have a factory manual... but I would be surprised if it wasn't in there.

Looking at replacement parts... 100amp appears to be standard.

I know the 130amp is the popular upgrade.

Tech Library over on The Ranger Station have some swap info.
 

LeBronCo

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Thanks Uncle G. I'll check out the Tech Section on TRS.
Nelson
 

duffy

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I was doing some reading on the subject and found everything from 65 to 85 amps listed as "stock". I would use a 90 or above for an upgrade.
 

Uncle Gump

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I was doing some reading on the subject and found everything from 65 to 85 amps listed as "stock". I would use a 90 or above for an upgrade.
You very well could be right...

I didn't deep dive it... I just looked at replacement parts offered at big box parts stores.
 

LeBronCo

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I kinda felt the same that 100 amps would make the old girl happy. Now I just need to find one that fits. I had to order three different starters to find the right one. I'm hoping to improve on that number this time. Don't you just love fixin' old things? LOL
Nelson
 

JerryC

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I think mine came with a 40 or 45 amp. I did lots of looking around and the easiest solution was to get a 90 amp from autozone.

The exact details are probably on here in a thread somewhere.

It's a direct bolt on. Much more than that and you might have a problem with a single v-belt driving it under load.

If you increase the amps you should also increase the size of the wire coming from the alternator.

You can also go to LED headlights to reduce your amp draw a bit. And they will make driving at night so much better.
 

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