Big 3 Question
 

Hey all,

I am doing my Big 3 with 0/1 welding wire. I was wondering what size fuse I should use for the alternator to battery fuse... I have no clue what size i need.

Assuming you have a 100 amp alternator, stick in at least a 130 amp fuse, if not a 150.

You want to go a lot more than your alternator's rating because a), when an alternator's cold, it can put out up to 20% more than it's rated for, and b), if you've replaced your stock battery with high effieciency gel types (Optima's, etc.), they make an alternator work harder (just like dropping resistance from speakers, makes your amps work harder, so does dropping the resistance in the battery make your alternator work harder).

It was a mouthfull, but I hope it all made sense. ;)

www.allstart.net/batadv.htm for more battery, alternator, and cabling advice.

Thanks a lot bro.

Why add any fuse at all? Of all the cars I have owned, the only one that had any kind of fuse between the alt and the batt was my Civic...

Theoretically if you are going to fuse the charge lead, it should be fused at each end, one at the battery, one at the alternator. Have fun.

i used 250 with 0/1 welding wire.

x2

No fuse on mine.

Wuw! thats crazy. I never thought of it like that. The alt puts out power and the battery puts out power so if there is only one fuse one of those things will start a fire depending upon what side of the fuse the wire grounds at, am I right????

Dukk and Hardwrkr, sounds like you guys are looking for a fuse and not a fuseable link which is generally between the starter and alternator or starter and battery. Very very few cars do not and have not had a fuseable link of some type. In most older Gm's there is a crapload of fuseable links at the starter, cleverly disguised as wires......


^^^^ yes you are right. This is why you also need to mount a fuse holder properly so that it does not make contact with anything else in the engine bay. (zap straps don't cut it either). Next ensure that the power wire from the alternator and the battery cannot chaff on anything (as the engine moves) and that the wire is not anywhere near anything hot.

Oh good, another "I fuse vs. I don't fuse" discussion on CCA.
cough*search*cough

If you want to put a fuse on this wire then go right ahead. Mine will stay unfused.

This doesnt help me... Should I just throw a 150 amp fuse on for the hell of it?

My amps will be making 2000w total, so I dont know how the flow of current will be...