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Upgrading Alternator

1926 Views 1 Reply 2 Participants Last post by  amerijeep
okay guys i need some help, when i go offroading at nite and use my lights, ny volt gauge drops drastically, i'm usuually running 4-6 100/130 watt lights, so i'm guessing another battery and a bigger alternator, what do you guys think? any suggestions would be nice, and helpful!

BTW i have a 1989 YJ stock engine and components, shackle lift, custom light bar, and i'm running 31's.

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· Retired Moderator
4,667 Posts
Well, you know that those lights have a draw of close to 50 amps. I forget what the alternator output is, but I am thinking it is around 80 amps. Those lights are starving your jeep for power. You want to get a high output alternator for sure. You shouldn't have any trouble finding one that will suit your needs. I'd go for about 130 amp alternator. You can find something to fit your needs at any parts store, alternator shop, Ebay, etc.

I really think that an extra battery is highly overated. Having an extra battery doesn't mean a thing if your alternator won't keep it charged. When the motor is running, you shouldn't be running off the battery at all. All the power should be coming from the alternator. An extra battery would only be useful if you needed power and didn't want to run your engine. The drop in amperage you describe, you are killing your battery when you run those lights. If you put in a second battery, you'll just ruin two of them.

Anyway, welcome to this brand new forum. Hope you get on here often. We need more YJ guys. The TJ guys are starting to get big heads.

Good luck and let us know what you decide to do with it.

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