Wire Upgrade ANL Fuse Size

I am upgrading my stock 1990 Comanche with 4 AWG wire for Battery, Charging, and Ground Cables per many of the posts on this site.

I have the stock RENIX Alternator and need to know what size of ANL Fuse is needed to protect the Alternator Cable?

Thank you for helping?

Safest policy for anything electrical is to overspec wiring and underspec fuses and breakers. Anyway you don't want a fuse that is larger than the maximum-rated alternator output. Stock alternator 1990 4.0 is 100 amps, so that is probably a good starting point. The ANL fuses are easy to swap so if you upgrade alternator you can upgrade fuse too.

You're talking about a fuse connected directly to the alternators output?

Some earlier Jeeps used a Mega-Fuse.

Chrysler replaced some of their vehicles using a Mega-Fuse with a fuse link.

Alternator output is a power source and normally protected separability from the fuse panel. It's not the same as an internal circuit connected to a fuse panel.

Alternator fuses or fuse links are designed to protect the alternator and battery.

Stock alternators are 60, 85 and 100 amp.

Remanufactured

JR775127 1 60 Ampere Tagged 110 1168
JR775126 1 85 Ampere Tagged 110 1170
JR775125 1 100 Ampere Tagged 110 1167

You may need to ask a Renix owner what the exact fuse size should be for a stock alternator and whether the fuse should be a slow blow.

Alternator fuses sometimes blow prematurely, if sized too low and respond to quickly to the alternators output. I think that might be one reason Chrysler changed some of their vehicles to a fuse link, which respond slower or similar to a slow blow fuse.

On advice from the tech support of a high output alternator manufacture, I fuse a little higher than the alternators maximum output rating.

Id use this guy: http://www.kelleyswip.com/electric.html

ANL fuse kit.

http://www.kelleyswip.com/anlkit.html

Read down the page further about ANL fuses.
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To select a fuse for your kit, you simply get one that is the same nominal rating as your alternator, or the next rating higher. (The 136A from our demonstration would take either a 140A or a 150A fuse - both are available, and it largely depends on what I have on hand at the time.) Note that alternator "true" output can vary by as much as -5/+10% from the "nominal" rating - again, using our 136A unit, I can see actual output of 130-150A from the thing. That's also at the nominal operating voltage of 13.6-14.5VDC.
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