I need to replace the cable going from my alternator to the battery, but when I try to follow it from the alternator... it looks like it's going down to the starter. Can anybody help me out?

 

BUMP!

This is something that I havent done yet, but need to upgrade from the stock 6ga to 1/0. I just havent gotten around to chopping up the great looming job that toyota did to hide all the wires...

 

The wire should run to the fusebox and from there to the battery (+). The starter is wired up directly (unfused) with larger wire to the battery's +. It can be different an various models though. I've got a lot of original wiring schematics, so if you need one....

 

Yeah, I just looked and saw that the wire runs to the fuse box. The only wire that connects from the fuse box to the battery looks way too small to be charging it (I estimate 16 ga. or smaller). Now the question remains... how do I go about upgrading this wire? I'm electronically inclined but I'm still kinda skittish about fooling with the fuse box. Is it easier than I'm thinking?

 

I have a 2001 Tacoma. The cable runs from the Alt to the fuse box. I installed an dual battery Isolator so I ran a new 4ga cable next to the stock cable. This has worked for almost 2 years now.

How/why did your cable fry?

ZR2Steve

 

There you go.

 

Well, I don't have a dual battery isolator nor do I plan on running 2 batteries. Or is there something I'm missing here? My stock cable didn't fry... I bought a 140 amp alternator from Mr. Alternator and I wanted to upgrade the stock cables so it would handle the extra current. If I'm understanding y'all right, all I'd need to do is upgrade the cable from the alt to the fuse box? What about the itty bitty cable going to the battery?

 

If I'm correct about this guess, it splits at the battery one wire to the factory fuse box and the other to the backside of the alternator. there's probably also a wire going to the starter from either the battery or the alternator. You should only need to upgrade to 4ga. from the alternator to the battery, and all this is doing is allowing your new higher amp alternator charge the battery more efficiently. Unless your running lots of lights, big stereo, etc... something thats pulling alot of current from your battery. You should also upgrade the ground wire from the battery to the factory ground spot probably somewhere on the fender to the same ga. wire as your charge wire. JM2C

example: this is all done in 1/0 like Bumpin suggested other than the piece of 8ga. going to the voltage regulator for voltage sense. This also has two more batteries under the back of the truck too.

 

I agree...most people overlook upgrading the ground with the positive...I just rewired my 4Runner's battery cables with 4ga and stuck in an Optima battery. It got to where it wouldnt crank unless you jiggled the positive battery terminal *haha*...I thought it might just be the terminal, but I figure its plenty old enough to deserve new 4ga wires all the way

 

I already knew I was going to upgrade to 4 ga. wire. What I'm confused about is where do I run the wire? Like this?...
[list=1][*]4 guage from alt to fuse box[*]4 guage from fuse box to battery[*]4 guage to body and engine ground[/list=1]

If this is how I should do it, I have no idea how I'm gonna run 4 guage to and from the fuse box. Anybody have any suggestions?

 

technically....a smaller wire will be fine for such a short distance ...meaning no need for 4ga wire for a few inches (battery to fuse box)...

I dunno if others will disagree with me on this...but a smaller wire can carry the same amps in a short distance as a larger wire would in longer distances...

Think about the fact that you can use regular network cable (rated at 10mbps) and run 1gig for about 10 feet just fine...but it cant handle that for a longer distance

 

If it were mine, I would run the 4ga. between the alternator output directly to the battery. Redoing the grounds from the battery the same way as the factory runs are just with 4ga. The factory ga. wire from the battery to the fuse box should be adiquate. Hope this clears up some confusion, any ?'s that I can help on email or pm me.

 

Churnd,
I have not done this, but from looking at the schematics, the alternator grounds to the frame, as does the battery. There are 2 white wires coming off the alternator. one of them goes through an 80 amp fuse at the fuse-box. With a higher amperage alternator you may need to up this fuse as well. The white wire then continues out of the fuse box and to the positive battery terminal. IMHO, if you were to replace these white wires, the fuse, and grounds, you should be in good shape as long as the fuse box can take the amperage.