Quick question about upgrading wire, I just ordered a new Alt.

 

Gold Member
Username: Invain

Michigan United States

Post Number: 3068
Registered: Aug-04
Well, my stock Alt. took a $hit, and since I now have to get a new one, I'm of course getting a H.O. alt. Anyways, I'm going from an 80a to a 160a. What size wire should I use for my big 3? I really don't know what size is in there right now, but I know I'll need bigger.
 

Bronze Member
Username: Winn

Santa Ana, California US

Post Number: 56
Registered: Jun-05
2 or 0 gauge ... I have my new H.O alternator (180amp) with 0gauge big 3
 

Gold Member
Username: Invain

Michigan United States

Post Number: 3069
Registered: Aug-04
Really, that big? I went out and looked, and stock is 8 gauge with the 80 amp alt. On the tech page of the site that I ordered from, for runs of 5 foot or less, and for alt's from 150 - 190 amp, the recommend at least 4 gauge. I'll probably just go with 2 to be safe. Now the question is, how much do I need. Do you remember how many feet you needed? Just a rough estimate would be great.
 

Bronze Member
Username: Winn

Santa Ana, California US

Post Number: 58
Registered: Jun-05
as short as possible joe.. It's depend on what car you have, my is about a little over 4 feet, since the alternator was sitting on the other side of the battery terminal.
 

Gold Member
Username: Invain

Michigan United States

Post Number: 3071
Registered: Aug-04
Yeah, I know as short as possible. There's 3 wires though. You got Alt to battery, battery to chassis, and then chassis to engine. That's gonna be a lot more than 4 feet. You can't just upgrade the positive lead from the alt to the battery and not upgrade the ground. I hope that's now what you did?
 

Bronze Member
Username: Winn

Santa Ana, California US

Post Number: 59
Registered: Jun-05
I meant 4 feet from alternator to the pos battery terminal. Ofcourse, I have to upgrade your ground to the chassis and chassis to the engine as well. But each of the length should not exceed over 5 feet. usuall 1-2 feet from chassis to the neg battery and 3 foot from my egine to chassis.

where to find it ? I got my Power wire (alternator to pos terminal) from the guy I bought the Alternator. for the ground and Engine wire, any auto shop they should have it.
 

Gold Member
Username: Invain

Michigan United States

Post Number: 3073
Registered: Aug-04
I'm probably just gonna have to go out and measure all the lenghts. My car's a little different, the positive lead from the alternator goes to the starter, then back up to the battery, so that's gonna be more than 5 feet. I don't think it will be a problem though since it's 2 seperate pieces. I was just wondering if anybody had a guesstimate at how much wire I would need total. I'm gonna end up just ordering however many feet of wire I need from knukonceptz.
 

Gold Member
Username: Invain

Michigan United States

Post Number: 3075
Registered: Aug-04
Anybody else? I have an idea now as to how many feet I need, but I'm still not sure whether I should get 4, or 1/0 awg. I'm gonna order from Knukonceptz, and all they have for 2 is the kompressed, so that's outta the picture.
 

Gold Member
Username: Invain

Michigan United States

Post Number: 3076
Registered: Aug-04
One more question. I've read about guys needing to put inline fuses right before the battery, because before they ran from the alt to the fuse box, then to the battery? Really doesn't make much sense to me... My car's wiring goes from alt. to starter, where wires split off, and some go to the fusebox, then from the starter to the battery. Why would I need an inline fuse before my battery if I don't already have one?
 

Bronze Member
Username: Kicker

Slave lake, Alberta Canada

Post Number: 73
Registered: Jun-05
joe smoe any idea why your alt. runs through your battery? dont see why it has to
 

Gold Member
Username: Invain

Michigan United States

Post Number: 3080
Registered: Aug-04
That made no sense man. Where else would it go? Of course your alt has to go to the battery...
 

Bronze Member
Username: Kicker

Slave lake, Alberta Canada

Post Number: 74
Registered: Jun-05
whoops i meant starter not battery

joe smoe any idea why your alt. runs through your starter? dont see why it has to
 

Gold Member
Username: Invain

Michigan United States

Post Number: 3081
Registered: Aug-04
Just the way it's made. It goes from the alt, down to a post bolt where everything else kinda branches off from. Then it goes up to the battery from the bolt. I still need to know the deal on the fuse thing though.
 

Bronze Member
Username: Kicker

Slave lake, Alberta Canada

Post Number: 75
Registered: Jun-05
and one more Q. what kind of vehicle?
 

Gold Member
Username: Carguy

Post Number: 3526
Registered: Nov-04
Joe Smoe, you can use 4gauge wires for your upgrade. Sure 2 gauge or lower is nice to have, but you will have tough time fitting it in your car. The reason why 4 gauge works for most HO upgrades is, the length is very short and the power surges are in bursts. Your amps will never use 180A of current constantly. If it did, then it's not music.
If you have a car shop, you can get 4 gauge "ground" wires with the ends for $10. No need to spend extra on "custom" wires.
 

Gold Member
Username: Carguy

Post Number: 3530
Registered: Nov-04
.
 

Gold Member
Username: Invain

Michigan United States

Post Number: 3082
Registered: Aug-04
What do you think about the fuse though? The only thing I could think of it doing is protecting the battery from overcharging. I guess with the fuse, it would blow and the only thing damaged would be the alt, instead of an exploded battery? I don't think I'm even gonna worry about it for now, unless somebody proves me wrong.
 

Gold Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 8002
Registered: Dec-03
4awg has a max rating of 15-A which decreases as you get longer cable.
you'll definately want 2ga for that setup
 

Gold Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 8003
Registered: Dec-03
as for fusing between battery and alternator, or battery and car interior, I'd go with a thermal circuit breaker, rated for 160A or so. that'll protect from dead shorts that'd cause a fire.

fuse appropriately for current draw at each amplifier using a fused distro block
 

Gold Member
Username: Invain

Michigan United States

Post Number: 3083
Registered: Aug-04
I knew I'd have to change the thermal breaker, I just tought what I had read was about something else. Do you think I'd be fine with a smaller breaker? Like 130 amp or so? I'd think 160 is pretty high, even if that's what the alt. is rated for, and I know I'm never gonna draw even close to 160 amps of juice. That's why I was gonna go with 4 gauge too. I know the amp is big enough for 2, but all I'm running is my car, and then 1 amp with a total of 80 amps worth of fuses. I had a good amount of headroom even with the 80 amp alt, as I was running an 400 wrms amp, and my voltage rails never sagged. 2 gauge is harder to find then 4, I was just planning on ordering 10 - 15 feet of 4 gauge from knukonceptz and calling it good. I'll get all the terminals and new battery connectors from our local shops.
 

Gold Member
Username: Invain

Michigan United States

Post Number: 3084
Registered: Aug-04
One final thing. I have a few questions about wiring in the alt. The one in my car is not internally regulated, and there are also the 2 wires for the dummy light in the dash. The new alt is 1 wire, internallly regulated, so what do I do about the dummy light? I don't wanna leve it unhooked and have it on all the time.

Also, my car doesn't have a ground directly from the engine to the chassis. It goes as follows: lead from alt to bolt on starter, then from the starter up to the battery. Then there's a main ground from the battery to a bolt on the engine, where other stuff is grounded as well. Then, there is a second smaller ground wire from the battery to the chassis, which my dad says is the thermal protector. That wire is what grounds the engine to the chassis, it's just connected at the battery as well. The small wire is made to melt when enough amps are run through, which breaks all circuits and prevents the fire. When I upgrade all my wiring, I'm of course gonna need to upgrade the engine to chassis wire, especially because the amp is grounded to the chassis. When I make that wire 4 gauge, it's not longer gonna be a thermal protector, so I'm thinking that is where the fuse comes in... Can I put a large fuse in, instead of a thermal circuit breaker?
 

Gold Member
Username: Invain

Michigan United States

Post Number: 3086
Registered: Aug-04
...
 

Bronze Member
Username: Kicker

Slave lake, Alberta Canada

Post Number: 80
Registered: Jun-05
"The small wire is made to melt when enough amps are run through, which breaks all circuits and prevents the fire"

could you not just double or tripple that wire? dont no much about electricle but cant see why not just thought anyways.
 

Gold Member
Username: Invain

Michigan United States

Post Number: 3092
Registered: Aug-04
I don't think that would be the greatest idea.
 

Bronze Member
Username: Kicker

Slave lake, Alberta Canada

Post Number: 83
Registered: Jun-05
just a thought
 

Bronze Member
Username: Winn

Santa Ana, California US

Post Number: 68
Registered: Jun-05
to finalize the question, If we use H.O Alternator, Do we really need the "Thermal Circuit Breaker" ? and where it should be install ?

Power line from Alternator to Battery Pos Terminal ?
 

Gold Member
Username: Invain

Michigan United States

Post Number: 3093
Registered: Aug-04
Everything else is fused in your vehicle, so if you get a surge it's protected. The only things not pretected are the battery, is something were to go wrong with the alt, and the wiring its self. The thermal circuit breaker would melt and break the circuit when enough current is present, preventing any of your wires to start on fire. I know chances are that it will never be used, but there's now way I wanna just drive around unpretected. I think I've decided to just use a fuse before the battery from the alt, instead of a thermal breaker. I think most thermal circuit breakers are usually either a ground wire themseles, or are inline with the ground from engine to chassis.
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