Little question about the big 3

[Notorious97200 339]

Hi everyone,

I'm looking to finish the big 3 in my car.

I already have a 0 ga wire from battery - to chassis.

My alternator is difficult to reach. I must "lift" the car to reach it under the motor.

My question is : can I take a point anywhere on the engine block and ground it to the chassis of the car (with a 0 ga wire) ? (I know !).

That would be the third part of the big 3.

I have a stock alternator, maybe the (+) alt to (+) battery part is not a "must do" part for me.

Another question : I have one 0 ga wire with ring connectors, and one 2/0 marine grade wire with ring connectors too. Which one would you choose for the battery to ground, and for the engine block to ground ?

Thanks

[j-roadtatts 1,129]

Yes you want the ground to the alt mount , but if not possible use the next closest point. YES the third link is from alt + to batt +, this wire lets the current flow directly to the battery with a path of least resistence. If you are leaving another factory ground somewhere ALSO, then use the 2ga there.

[mr.sagat 10]

Hi everyone,

I'm looking to finish the big 3 in my car.

I already have a 0 ga wire from battery - to chassis.

My alternator is difficult to reach. I must "lift" the car to reach it under the motor.

My question is : can I take a point anywhere on the engine block and ground it to the chassis of the car (with a 0 ga wire) ? (I know !).

That would be the third part of the big 3.

I have a stock alternator, maybe the (+) alt to (+) battery part is not a "must do" part for me.

Another question : I have one 0 ga wire with ring connectors, and one 2/0 marine grade wire with ring connectors too. Which one would you choose for the battery to ground, and for the engine block to ground ?

Thanks

Well, the grounds of the big 3 are important, but imo will not make as dramatic of a difference as the positive run from the alt. Here's my reasoning. Almost all vehicles already have battery ground to chassis and chassis to engine block grounds ran. These are usually a little thick, (2-6 gauge) and are usually short lengths too. The alt wire, is usually some puny wire (10-14) gauge and is usually a lot longer run (could be up to 6-8 feet) then the ground wires of the big 3. So wire wise, your making a night and day difference between the positive, but only a dusk to dark difference between the grounds.

Edited April 12, 2010 by mr.sagat

[Notorious97200 339]

Yes you want the ground to the alt mount , but if not possible use the next closest point. YES the third link is from alt + to batt +, this wire lets the current flow directly to the battery with a path of least resistence. If you are leaving another factory ground somewhere ALSO, then use the 2ga there.

The 2 wires I already have are one 1/0 and one 2/0( the bigger one).

Which one to use for what grounds ?

"the next plosest point" : so, I should not use any point from the engine block ? You think I need to go close to the alternator.

MR Sagat : you think the alt(+) to batt (+) is the most important part to do ? I'm surprised. I thought this stock wire should be at the good size for the stock alternator. I don't have no high output aftermarket alt.

[mr.sagat 10]

Yes you want the ground to the alt mount , but if not possible use the next closest point. YES the third link is from alt + to batt +, this wire lets the current flow directly to the battery with a path of least resistence. If you are leaving another factory ground somewhere ALSO, then use the 2ga there.

The 2 wires I already have are one 1/0 and one 2/0( the bigger one).

Which one to use for what grounds ?

"the next plosest point" : so, I should not use any point from the engine block ? You think I need to go close to the alternator.

MR Sagat : you think the alt(+) to batt (+) is the most important part to do ? I'm surprised. I thought this stock wire should be at the good size for the stock alternator. I don't have no high output aftermarket alt.

Let's think of it this way. We have a completely stock car with no audio at all. The starting system on a car may drain 100-150 amps when you "start her up" That may be about 3 or 4 foot of 6 gauge in the worst case scenario and is only used for a few seconds. The alt on the other hand, will have about 6 foot of 10 gauge in the best case scenario. The alt might be rated for 130 amps, and in a stock car scenario that is fine. The alt is usually never under high loads, and the only thing that even begins to strains a stock cars charging system is a weak, or discharged battery. So the stock alt never really gets abused like it would in car audio. In audio that alt might be putting her max amperage through her power wire as long as it runs and your beating the block down.

Ok, lets go back to the stock alt wire, I said in the best case scenario it's 10 gauge right? The max amperage on the alt it's connected to is 130. That is the same as a 1500-1600 rms amplifier. Everyone knows that a 1600 rms amp needs more than 10 gauge. You get what I'm saying?

In case you wondering how I converted the amperage over to wattage, I used a formula. (Amperage x Voltage = wattage)

[jcarter1885 995]

To answer your question simply, I would put the bigger wire 2/0 AWG on battery to chassis ground and smaller wire 1/0 AWG on engine block to chassis ground

[mr.sagat 10]

yeah dude, sorry for such a lengthy post. If I was doing this in a ship and followed ABYC standards, I'd have to make the ground equal size or larger than the power wire. But this is the real world, and I can assure you you'll be just fine making the 1/0 ground.

[Notorious97200 339]

Thanks for your answers !

Last questions :

1) Is it good (or worth it) to take a point on the engine block not so close of the alternator to ground it on the chassis ?

2) What lenghth all these ground wires got to have (minimum, and MAXIMUM) ?

[j-roadtatts 1,129]

Thanks for your answers !

Last questions :

1) Is it good (or worth it) to take a point on the engine block not so close of the alternator to ground it on the chassis ?

2) What lenghth all these ground wires got to have (minimum, and MAXIMUM) ?

YOu honestly will be fine grounding any where on the engine, as long as its solid.

Less than 18" is prefered, but once again not that important.

[johnecon2001 82]

Lot of misinformation in this thread.

All the points in the Big 3 are important. Without doing one of them you may as well do none of them.

Grounding points are just as important if not more important than the positive power points. Use the 2/0awg wire on the ground point under the hood. It doesn't matter where you attache it as long as its a good solid clean spot attached to a non essential bolt of the engine. The other side should be on clean sanded metal of the chassis.

Even without a High Output alternator, the positive leg is still important. *Remember* you're not replacing cable, you're adding to the stock cable. Use your 1/0awg wire here.

Post here with any other questions.

[mr.sagat 10]

Lot of misinformation in this thread.

All the points in the Big 3 are important. Without doing one of them you may as well do none of them.

Grounding points are just as important if not more important than the positive power points. Use the 2/0awg wire on the ground point under the hood. It doesn't matter where you attache it as long as its a good solid clean spot attached to a non essential bolt of the engine. The other side should be on clean sanded metal of the chassis.

Even without a High Output alternator, the positive leg is still important. *Remember* you're not replacing cable, you're adding to the stock cable. Use your 1/0awg wire here.

Post here with any other questions.

whoa, misinformation? I used to be an AC and DC Electrician on 12/24 and 110/220 volt systems. I had to take American Boat and Yacht council exams about these things. LOL I've also got a two ASE Certifications in automotive.

I'm not saying that the grounds on the big 3 are not important, they just make less of an impact than the power wire can. If cars had 10 gauge grounds, then that would make a HUGE difference. But they don't. They usually have 4 or 6 gauge and it's a short run at that. (less than 18 inches on my Cadillac)

What I am trying to say is this. If you're going from a 6 gauge to a 1/0 ground you are about doubling the thickness of the wire for all of it's 18 inches of length. If you have a 10 gauge alt wire and add a 1/0 alt wire you are more than tripling the diameter of the wire and your doing it for it's whole length, which is almost always longer than the grounds.

[Notorious97200 339]

Lot of misinformation in this thread.

All the points in the Big 3 are important. Without doing one of them you may as well do none of them.

Grounding points are just as important if not more important than the positive power points. Use the 2/0awg wire on the ground point under the hood. It doesn't matter where you attache it as long as its a good solid clean spot attached to a non essential bolt of the engine. The other side should be on clean sanded metal of the chassis.

Even without a High Output alternator, the positive leg is still important. *Remember* you're not replacing cable, you're adding to the stock cable. Use your 1/0awg wire here.

Post here with any other questions.

Ok, I understand everything is important ! I have just one battery, and it's under the hood. No batt at the back, in the trunk.

So, I use the 2/0 awg wire for engine block to chassis (ground).

The 1/0 awg wire for the battery(-) to chassis (ground).

I must get some more 1/0 awg wire and ring connectors to do the alt(+) to batt(+).

I got it NOW !!!

I will tell you how I feel it when it's done ! When I upgraded the ground on the battery, I saw a better voltage number on my voltmeter.

My car still run fine, no voltage loss, but it is just to run it safer !

This forum is too coooool !

thanks a lot.

[jcarter1885 995]

Lot of misinformation in this thread.

All the points in the Big 3 are important. Without doing one of them you may as well do none of them.

Grounding points are just as important if not more important than the positive power points. Use the 2/0awg wire on the ground point under the hood. It doesn't matter where you attache it as long as its a good solid clean spot attached to a non essential bolt of the engine. The other side should be on clean sanded metal of the chassis.

Even without a High Output alternator, the positive leg is still important. *Remember* you're not replacing cable, you're adding to the stock cable. Use your 1/0awg wire here.

Post here with any other questions.

Thats definitely not true, I seen gains just by upgrading my ground wires alone. I can agree that Im not getting the full benefit if I did the whole Big 3 process but doing the Big 2 made a difference but to each its own. But if you do it, you minus well do all three wires I will agree with that (since my stock battery is in the trunk Im just waiting till I replace my alternator to do the wire plus its 4 gauge anyway so Im cool for now).

[Don Ganso 13]

I have a question: (This is from denim's big 3 guide in the tech/how to section)

The Big 3 Are:

1. negative battery wire to ground - just replace the negative batt. terminal and wire and ground it to the factory location

2. engine block to ground - replace the ground wire from the engine block to the chasie with a bigger wire (maybe 4 guage)

3. alternator to batt - add a fused wire from the postive post on you alternator (the one comming from the battery) to the postive terminal on your battery. DO NOT exchange wires just add a extra one. make sure it fused the same size as your factory fuse.

hope thats helps

Note on #2- Some cars have a batt-engine block connection stead of chassis to engine block..

So wait a minute, I want to limit the power my alt can give my battery? What if I had an H/O alt? This wouldn't make sense IMO. I could see fusing to the wire's amp rating or something, but how is more amperage going to hurt the battery and/or car? Sorry if this post detracts from the OP's question, johnecon just said to post 'em up, so I did.

[mr.sagat 10]

I have a question: (This is from denim's big 3 guide in the tech/how to section)

The Big 3 Are:

1. negative battery wire to ground - just replace the negative batt. terminal and wire and ground it to the factory location

2. engine block to ground - replace the ground wire from the engine block to the chasie with a bigger wire (maybe 4 guage)

3. alternator to batt - add a fused wire from the postive post on you alternator (the one comming from the battery) to the postive terminal on your battery. DO NOT exchange wires just add a extra one. make sure it fused the same size as your factory fuse.

hope thats helps

Note on #2- Some cars have a batt-engine block connection stead of chassis to engine block..

So wait a minute, I want to limit the power my alt can give my battery? What if I had an H/O alt? This wouldn't make sense IMO. I could see fusing to the wire's amp rating or something, but how is more amperage going to hurt the battery and/or car? Sorry if this post detracts from the OP's question, johnecon just said to post 'em up, so I did.

Just install a fuse that is equal to or a little higher than the alt's max amperage.

The fuse isn't there to limit the charge from your alt, it's there in case something goes wrong.

The fuse will burn out and there will be no signal past the burned fuse. Lets say a fender bender occurs that crushes your alt power wire in between a metal fender and engine block. Well, that huge wire you just installed is now making direct contact with the ground of the car. Without a fuse to pop, You can guarantee there will be a fire.