Big three upgrade question

[ChaseinBass]

I am doing a big three upgrade on my 96 gmc truck and all done except the Alt to battery lead and i notice factory small wire has a fused link in it > my question is should i Put an inline fuse in my 0 gauge also ? And if so How do I determine Fuse size ?

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[mylows10 5,000+ posts]

You can if you like some do some don't. The fuse size depends on alt size

 

[ChaseinBass]

So if I have 100 amp alt i need 100 amp fuse ? or higher ?

 

[fruitwerks]

Really, I would not bother to put a fuse there, especially with a wiring UPGRADE. But if you want... To figure out what amperage you need, take a look at your main fuse box under the hood, find the biggest fuse and go with that rating for the alternator fuse. For example on my car, the biggest fuse is a 50A. Also make sure it is a fuse and not something funny like a thermal cutoff or diode.

 

[Oraclem19]

So if I have 100 amp alt i need 100 amp fuse ? or higher ?

This is almost right.

Really, I would not bother to put a fuse there, especially with a wiring UPGRADE. But if you want... To figure out what amperage you need, take a look at your main fuse box under the hood, find the biggest fuse and go with that rating for the alternator fuse. For example on my car, the biggest fuse is a 50A. Also make sure it is a fuse and not something funny like a thermal cutoff or diode.

This is nowhere near right.

If you have an alt that will output 100 amps at full power, I would add 10% up to 20% to this number to allow for full power capabilities. On a 100 amp alt put the nearest size fuse to this. 125 amp or 150 amp. A 100 amp fuse on a 100 amp alt has the possibility to blow the fuse just from running, not from shorting.

I do not see why you need a fuse between alternator and battery though.