What size fuse for big 3?

[RollinRemz05 10+ year member]

What size fuse should I be using when doing the big 3? The power wire from alt to the batter. My alternator is 90 amps and I have a red top if that helps and I am using 4 guage wire. Thanks alot!

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[jacka 10+ year member]

i believe its 120A for a 4 gauge wire.

 

[RollinRemz05 10+ year member]

anyone else?

 

[nbro3232 10+ year member]

the fuse has little to do with size of wire but more of what your amp puts out. if yours is 90 you want something over 90 so if there is a jump in amperage the fuse will trip

 

[RollinRemz05 10+ year member]

My amp is putting out the 600 rms @ 1 ohm and on the amp I have 2 35A fuses. What size fuse should I use for the power wire to the amp? Is it ok to use a 100A fuse for my alternator then? Since its putting out 90 amps? Thanks.

 

[nbro3232 10+ year member]

im not sure, im sure someone with more knowledge will chime in

 

[klepto 10+ year member]

Is it absolultey necessary to fuse this line if you are doing hte big 3? I just ordered a bunch of 0ga to do the Big 3 and i didnt order another fuse...

 

[da12b 10+ year member]

I also upgraded my "BIG 3" using 4 ga. cable. I did a lot or research on what fuse to use and I found out that the max fuse rating is 150 ampere rating. That is what I'm using now.

The fuse is to protect the alternator from being "FRIED." French Fries anyone...lol

Hope this helps

 

[RollinRemz05 10+ year member]

You should fuse the wire for the big 3 so you dont catch your car on FIRE! =D woulnt be too good...

 

[PhatTonyDeMarco 5,000+ posts]

the fuse has little to do with size of wire but more of what your amp puts out. if yours is 90 you want something over 90 so if there is a jump in amperage the fuse will trip

100% incorrect buddy... The wire size has EVERYTHING to do with the fuse size. 120-150A would be fine for 4 guage wiring.

I do suggest using at least 1/0 awg wiring for the Big Three, anything else and you are wasting your time...

 

[da12b 10+ year member]

You might also consider changing your 90 ampere alt to a H.O. alt.

Check out http://www.4alterstart.com

 

[stuckinok 5,000+ posts]

you really dont need a fuse on a 90amp alternator using 4ga i mean its even optional but recomended if you use 1/0ga so if your using 4ga you dont need to fuse it. Only if you want to. Read the Big three article

 

[stuckinok 5,000+ posts]

100% incorrect buddy... The wire size has EVERYTHING to do with the fuse size. 120-150A would be fine for 4 guage wiring.
I do suggest using at least 1/0 awg wiring for the Big Three, anything else and you are wasting your time...

Anything over stock is a improvment most cars come with 8ga so even using 4ga is an improvement but like most people say since your doing all the work you might as well do it right the first time and go big

 

[Steven206Seattl 10+ year member]

What about a 90 amp altenator using 400 watts and 4 gauge wire and has a 50 amp fuse? Is that too small?

 

[Fast1one 10+ year member]

Anything over stock is a improvment most cars come with 8ga so even using 4ga is an improvement but like most people say since your doing all the work you might as well do it right the first time and go big

MOST....mine came with 4 gauge stock...