Does BIG 3 need fuse?

[ObTechAudio]

So I'm doing a big 3 upgrade and I have a simple question, does the positive connection from the alternator to (+) of battery need a fuse? If so how big? ANL 250 amp?

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[Dmac1991]

I've always known to fuse it, but as of late, people have been saying not to fuse it, because if it blows, your alt won't be charging.

So for the sake of it, I'd fuse it. Rather be safe than sorry

and the fuse solely depends on the wire gauge you use. I presume that you're using 0 gauge, so yes 250a would be fine

 

[mylows10 5,000+ posts]

The fuse protects your cars system from a alt spike it really depends on what your doing here. In competition I'd say. no. For daily. Then yes

 

[yogegoy]

I've always known to fuse it, but as of late, people have been saying not to fuse it, because if it blows, your alt won't be charging.
So for the sake of it, I'd fuse it. Rather be safe than sorry

and the fuse solely depends on the wire gauge you use. I presume that you're using 0 gauge, so yes 250a would be fine

As long as you have easy access to the fuse and carry spares or still the same outcome that you're going to be stuck wherever you are because of a $10 or less fuse couldn't be replaced. I suggest a 300A for a 0ga right next to the battery from your alt.

 

[shauncox26]

if u leave the factory wires like i always do ur alt should still charge, the fuse would be to protect the bat and alt in the case the wire is cut or burnt and shorts out

 

[ObTechAudio]

Awesome thank you guys for all of your help. So going off of what "shauncox26" said, should i also leave the factory wire from alt to battery and just add my 0ga to it or replace it completely?

 

[Mass Car Audio 10+ year member]

I never fuse my big 3.

 

[mylows10 5,000+ posts]

Always add never remove

 

[audiobaun 5,000+ posts]

No fuses on any of my big 3 setups..Ive never had any issues up to date.Even on the daily around town vehicle.But 0ga/250-300max

 

[72Impala 10+ year member]

My big 3 is done in 4/0 welding cable without a fuse and I have yet to see an issue. But I should probably be using one, the factory uses a fuse from alt to batt, so we probably should be too.

 

[ObTechAudio]

Thank you all for helping me out with my questions

 

[OzNath 10+ year member]

I didn't fuse mine either, no problems yet after a year =)

 

[bubbagumper6 5,000+ posts]

Not using a fuse will not cause any immediate problems, but when your wire get's cut/pinched/corroded/etc and ends up shorting out to the chassis and causing your battery to explode you'll regret it. It's like saying "Well I've been driving for years without a seatbelt and never had a problem."

If you're competing and looking for every 1/10th of an amp you can get from your alternator then by all means disregard the fusing. But if we're talking about a daily driver you absolutely should be using fuses.