Big 3 upgrade - how should I fuse

[Goldtaz1 10+ year member]

I am going to be doing the big 3 wiring upgrade in the not so distant future and I would like someone to help me understand the concept of fusing. I have read things that suggest that your fuse should be just large enough to support the total load your amplifiers are capable of pulling, but I have also read material that states that fusing is meant to protect the wiring that you use. I have purchased a 300 amp fuse for the wire that will run from my alternator to the battery positive, is this incorrect?? Please help. //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

Click to read more...

 

[saywhat? 5,000+ posts]

i dont think it will hurt if it is an overload for a fuse.

 

[lexus rx 10+ year member]

no fuse needed. your alt. will only send as much power to the battery as needed. whatever fuse you have running from the battery to the amp its what you want. you will be fine with no fuse.

 

[Goldtaz1 10+ year member]

I just wanted to say thanks for clearing up this issue for me.

 

[sumone 10+ year member]

1. fuses protect wire

2. they protect electrical equipment (an amp for instance)

3. they protect you...

if you wanted to be the safest mofo on the block, every circuit in the car's electrical system

should be fused...

however, if I were you, I'd fuse that alternator wire. I've got 1/0 for that wire fused with a 250A fuse. With such a thick wire, if for instance that unfused wire were to get cut and shorted out in an accident...well, it's a done deal...

 

[`pr0digy 10+ year member]

no fuse needed. your alt. (as long as it's working correctly) will only send as much power to the battery as needed. whatever fuse you have running from the battery to the amp its what you want. you willprobably be okay, but it's still a good idea

edit for quotes

 

[JimJ 5,000+ posts]

yeah...fuse that wire...

in the event of a short, your alternator is safe, but now your battery is looking at a dead short to ground. Major bad news if that's an unfused wire.

 

[Goldtaz1 10+ year member]

I appreciate all of your responses. I have completed 2 out of the three wires and I have already seen a difference in my charging voltage. The third wire (alternator positive to battery positive) is going to take a little time because I have a Mazda Protege' 5 and the **** alternator is under the engine down by the front left wheel of the car. Who in the hell thinks of doing that kind of crap? At any rate it will be done. One thing I will tell you is that I was completely floored by how poorly the original ground was done by the automaker. The old ground was not metal to metal in the sense that they had not scratched the paint off. In my experiences I have always been told that the best ground comes from a good metal to metal connection, meaning scrape the freakin paint off!! I guess the automaker doesn't take into account people like all of us putting in crazy systems that crave tons of power. Peace. //content.invisioncic.com/y282845/emoticons/peace.gif.2db28b618ed8d1964ebbe2f5021d2c39.gif

 

[JimJ 5,000+ posts]

The battery ground is one of the simplest upgrades you can do to the charging system...amazing how some people neglect that.

And I share your pain about the alternator //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif Ford, in their infinite wisdom, shoved the alternator underneath the air intake...so I have to take off the intake just to get to the alternator connection. That's something about a van that *****...short hoods = no room to work on things. I have to change the spark plugs from inside the cab! :/