negative battery > chassis
Thread Starter
Registered!!
iTrader: (1)
Joined: Nov 2004
Posts: 1,446
Likes: 0
From: 707
Rep Power: 276 
negative battery > chassis
i read off another thread, cant find it, but a member hooked up 4 awg from his negative battery terminal to the car chassis. he claims his dimming was gone and its a cheaper solution than a capacitor.
is this true? any downfalls to it in the long run?
is this true? any downfalls to it in the long run?
Electric Boogaloo...
iTrader: (6)
Joined: Mar 2003
Posts: 4,457
Likes: 1
From: Want to play a game?
Rep Power: 328 
Cause I'm too fucking lazy to type it:
As many of you know, upgrading the "Big 3" wires in your engine compartment can lower the overall resistance of your entire electrical system. The effects of the lower resistance are typically:
1) Reduced dimming and smaller voltage drops
2) More stable voltage and better current flow
3) Less strain on your vehicle's charging system
So for those of you looking for a cheap and easy way to upgrade your system and help out your electrical system without adding a high output alternator or an aftermarket battery, this is the modification for you. If you have heavy dimming or are getting large voltage drops during loud bass hits, but you don't have the money to spend on a high output alternator or a battery, upgrading your vehicle's "Big 3" will usually help to reduce and sometimes even eliminate the problems. So without further ado, the "Big 3" wires are:
1) Battery negative to chassis
2) Alternator to battery positive
3) Chassis to engine
Now, I suppose it would help if I explained what each of these wires does, and to do that I would like to paraphrase an explanation by IMTfox from a while ago: Think of your vehicle's charging system as two different circuits, one consisting of your amplifier and your battery, and the other consisting of your alternator and your battery. The current in your electrical system flows from your positive battery terminal to your amp, from your amp's ground to the chassis, and then from the chassis back to the negative battery terminal. But how does it get to the positive terminal in the first place? That's where the alternator comes in. Current in the second circuit flows from your alternator's positive post to the battery's positive terminal, then from the battery's negative terminal to the chassis, and from the chassis back to the block, which happens to be the grounding point for your alternator.
So, from your battery, you have the power wire going to the power terminal on your amplifier and then your amplifier is grounded to the chassis of the vehicle. From here the current needs a way to get back to the negative battery terminal, and that way is through the first of the "Big 3," the battery negative to chassis wire. Upgrading this wire will "upgrade" the circuit between your battery and your amp by giving the current a larger path to flow through to get back to the battery.
Now, think of your alternator as the battery and your battery as the amp. From the positive post on your alternator, you have the second of the "Big 3," the alternator to battery positive wire supplying "power" to your battery. From there the battery, just like your amp, is grounded to the chassis through the wire mentioned in the previous paragraph. Again, the current needs a way to get from the chassis back to the alternator's "negative terminal" and that way is through the last of the "Big 3," the chassis to engine wire. Since your alternator is most likely mounted to your engine block using a metal or conductive mounting bracket, you can simply add your new wire from the chassis to one of the mounting posts for the alternator. Upgrading these two wires will "upgrade" the circuit between your alternator and your battery, again giving the current a larger path to flow through.
----------------------------------------------
Now that you understand exactly what the "Big 3" do, it's time to upgrade them to a larger gauge wire. You can use regular power wire from installing your car audio equipment, ring terminals, and crimping equipment just the same as you would for any other install. Let's start with the first of the "Big 3," the battery negative to chassis wire:
1) Disconnect your battery's negative terminal and get the stock wiring out of the way. You might have to cut it and crimp a new ring terminal onto it. I found it helpful to use aftermarket battery terminals with multiple ports on them also.
2) Scrape away the paint and drill the hole for your connection of the larger wire, or connect it to the stock grounding point. Either way you do it, make sure it is bare chassis metal, not covered by paint, and that the connection is as tight and secure as possible:
-
-
3) Secure the new wire to the chassis and reconnect the vehicle's stock chassis ground, but DON'T reconnect the vehicle's negative battery terminal yet! You may find it helpful to cover the negative battery terminal with a cloth or other non-conductive material and just lay the terminal on it until you're ready to reconnect it later.
Moving on to the next of the "Big 3," let's upgrade the alternator to battery positive wire:
4) Locate the vehicle's alternator and look for a terminal post connected to it. The post shouldn't be hard to find. It should have only one wire connected to it, and it should lead to the positive terminal on the battery, possibly through the fuse box.
-
5) Disconnect the stock alternator to battery positive wire from the positive post and connect it to the post again with the new wire added.
6) Run the wire either through your fuse box if applicable or through a fuse. The fuse should be sized to match the max ampacity of your wire, not the output capability of your alternator. As you can see I just went through the fuse box, so my upgrade is probably not making as much of a difference as it could if it were fused externally, but my alternator is capable of withstanding the draws anyway so I'm not particularly worried about it. If I ever begin to see a problem w/ current draws, I will probably fuse the wire externally with a 300A or so fuse...
7) From the fuse, connect the wire to the positive terminal on your battery, again, leaving the stock wiring connected when you're done. The picture below shows the alternator to battery positive wire run from the alternator through my fuse box to the positive battery terminal.
-
Last, let's move to the chassis to engine wire: (Again, because your alternator is grounded to the block, all you need to do is find a bolt somewhere on the block and connect it to the chassis. The alternator's mounting bracket is usually a good place to find these bolts).
8) Again, either drill a new hole or connect this wire to the stock chassis ground. From the chassis ground, run the wire back to one of the mounting posts for the alternator (or to a bolt on the engine block).
-
9) That's it! You're done. Reconnect the vehicle's negative battery terminal and check out the difference! Below is a shot of the "Big 3" upgraded in my car. The other wire you see coming out of the battery's positive terminal is obviously my amp's power wire.
-
----------------------------------------------
Helpful hints:
1) Leave the stock wiring attached after you're done. Don't replace the stock wiring, add onto it. Current will take the path of least resistance anyway, so replacing the stock wire will only make more work for yourself.
2) When fusing your alternator to battery positive wire, fuse it toward the battery end of the wire. As IMTfox points out later in this thread, the battery will explode if it's overloaded, while the alternator will only burn out its regulator which won't cause much damage except to the alternator itself. Exploding batteries are no fun!
3) When crimping large gauge terminals for 1/0awg and sometimes even 4awg, a vice works well. Crimp one side of the terminal at a time, creating an overlapping edge. Put the boot around this and then wrap it in electrical tape if you want. the most secure connections will occur in this way.
-
-
4) Lastly, prepare all your materials and tools BEFORE you are ready to upgrade. Know what you are doing before you start so you can be done as quick as possible. The majority of vehicles have computers that will reset after the battery is disconnected for a long time and they can cause older vehicles to do strange things if they reset.
Hopefully this clears up most of the questions you had about why we upgrade the "Big 3" and how it helps to stop dimming and other electrical problems
As many of you know, upgrading the "Big 3" wires in your engine compartment can lower the overall resistance of your entire electrical system. The effects of the lower resistance are typically:
1) Reduced dimming and smaller voltage drops
2) More stable voltage and better current flow
3) Less strain on your vehicle's charging system
So for those of you looking for a cheap and easy way to upgrade your system and help out your electrical system without adding a high output alternator or an aftermarket battery, this is the modification for you. If you have heavy dimming or are getting large voltage drops during loud bass hits, but you don't have the money to spend on a high output alternator or a battery, upgrading your vehicle's "Big 3" will usually help to reduce and sometimes even eliminate the problems. So without further ado, the "Big 3" wires are:
1) Battery negative to chassis
2) Alternator to battery positive
3) Chassis to engine
Now, I suppose it would help if I explained what each of these wires does, and to do that I would like to paraphrase an explanation by IMTfox from a while ago: Think of your vehicle's charging system as two different circuits, one consisting of your amplifier and your battery, and the other consisting of your alternator and your battery. The current in your electrical system flows from your positive battery terminal to your amp, from your amp's ground to the chassis, and then from the chassis back to the negative battery terminal. But how does it get to the positive terminal in the first place? That's where the alternator comes in. Current in the second circuit flows from your alternator's positive post to the battery's positive terminal, then from the battery's negative terminal to the chassis, and from the chassis back to the block, which happens to be the grounding point for your alternator.
So, from your battery, you have the power wire going to the power terminal on your amplifier and then your amplifier is grounded to the chassis of the vehicle. From here the current needs a way to get back to the negative battery terminal, and that way is through the first of the "Big 3," the battery negative to chassis wire. Upgrading this wire will "upgrade" the circuit between your battery and your amp by giving the current a larger path to flow through to get back to the battery.
Now, think of your alternator as the battery and your battery as the amp. From the positive post on your alternator, you have the second of the "Big 3," the alternator to battery positive wire supplying "power" to your battery. From there the battery, just like your amp, is grounded to the chassis through the wire mentioned in the previous paragraph. Again, the current needs a way to get from the chassis back to the alternator's "negative terminal" and that way is through the last of the "Big 3," the chassis to engine wire. Since your alternator is most likely mounted to your engine block using a metal or conductive mounting bracket, you can simply add your new wire from the chassis to one of the mounting posts for the alternator. Upgrading these two wires will "upgrade" the circuit between your alternator and your battery, again giving the current a larger path to flow through.
----------------------------------------------
Now that you understand exactly what the "Big 3" do, it's time to upgrade them to a larger gauge wire. You can use regular power wire from installing your car audio equipment, ring terminals, and crimping equipment just the same as you would for any other install. Let's start with the first of the "Big 3," the battery negative to chassis wire:
1) Disconnect your battery's negative terminal and get the stock wiring out of the way. You might have to cut it and crimp a new ring terminal onto it. I found it helpful to use aftermarket battery terminals with multiple ports on them also.
2) Scrape away the paint and drill the hole for your connection of the larger wire, or connect it to the stock grounding point. Either way you do it, make sure it is bare chassis metal, not covered by paint, and that the connection is as tight and secure as possible:
-
-
3) Secure the new wire to the chassis and reconnect the vehicle's stock chassis ground, but DON'T reconnect the vehicle's negative battery terminal yet! You may find it helpful to cover the negative battery terminal with a cloth or other non-conductive material and just lay the terminal on it until you're ready to reconnect it later.
Moving on to the next of the "Big 3," let's upgrade the alternator to battery positive wire:
4) Locate the vehicle's alternator and look for a terminal post connected to it. The post shouldn't be hard to find. It should have only one wire connected to it, and it should lead to the positive terminal on the battery, possibly through the fuse box.
-
5) Disconnect the stock alternator to battery positive wire from the positive post and connect it to the post again with the new wire added.
6) Run the wire either through your fuse box if applicable or through a fuse. The fuse should be sized to match the max ampacity of your wire, not the output capability of your alternator. As you can see I just went through the fuse box, so my upgrade is probably not making as much of a difference as it could if it were fused externally, but my alternator is capable of withstanding the draws anyway so I'm not particularly worried about it. If I ever begin to see a problem w/ current draws, I will probably fuse the wire externally with a 300A or so fuse...
7) From the fuse, connect the wire to the positive terminal on your battery, again, leaving the stock wiring connected when you're done. The picture below shows the alternator to battery positive wire run from the alternator through my fuse box to the positive battery terminal.
-
Last, let's move to the chassis to engine wire: (Again, because your alternator is grounded to the block, all you need to do is find a bolt somewhere on the block and connect it to the chassis. The alternator's mounting bracket is usually a good place to find these bolts).
8) Again, either drill a new hole or connect this wire to the stock chassis ground. From the chassis ground, run the wire back to one of the mounting posts for the alternator (or to a bolt on the engine block).
-
9) That's it! You're done. Reconnect the vehicle's negative battery terminal and check out the difference! Below is a shot of the "Big 3" upgraded in my car. The other wire you see coming out of the battery's positive terminal is obviously my amp's power wire.
-
----------------------------------------------
Helpful hints:
1) Leave the stock wiring attached after you're done. Don't replace the stock wiring, add onto it. Current will take the path of least resistance anyway, so replacing the stock wire will only make more work for yourself.
2) When fusing your alternator to battery positive wire, fuse it toward the battery end of the wire. As IMTfox points out later in this thread, the battery will explode if it's overloaded, while the alternator will only burn out its regulator which won't cause much damage except to the alternator itself. Exploding batteries are no fun!
3) When crimping large gauge terminals for 1/0awg and sometimes even 4awg, a vice works well. Crimp one side of the terminal at a time, creating an overlapping edge. Put the boot around this and then wrap it in electrical tape if you want. the most secure connections will occur in this way.
-
-
4) Lastly, prepare all your materials and tools BEFORE you are ready to upgrade. Know what you are doing before you start so you can be done as quick as possible. The majority of vehicles have computers that will reset after the battery is disconnected for a long time and they can cause older vehicles to do strange things if they reset.
Hopefully this clears up most of the questions you had about why we upgrade the "Big 3" and how it helps to stop dimming and other electrical problems
right off that sound domain site huh? haha
http://forum.sounddomain.com/forum/u...=5;t=007801;p=
so therefore, doing only 1 (neg > chassis) of the 'big-3' is still an improvement?
http://forum.sounddomain.com/forum/u...=5;t=007801;p=
so therefore, doing only 1 (neg > chassis) of the 'big-3' is still an improvement?
Electric Boogaloo...
iTrader: (6)
Joined: Mar 2003
Posts: 4,457
Likes: 1
From: Want to play a game?
Rep Power: 328 This paragraph: So, from your battery, you have the power wire going to the power terminal on your amplifier and then your amplifier is grounded to the chassis of the vehicle. From here the current needs a way to get back to the negative battery terminal, and that way is through the first of the "Big 3," the battery negative to chassis wire. Upgrading this wire will "upgrade" the circuit between your battery and your amp by giving the current a larger path to flow through to get back to the battery.
Joined: Oct 2002
Posts: 4,248
Likes: 2
From: Rockville, Maryland
Rep Power: 331 ^well put...think about it...OEM ground from your battery is 8 awg. Youre most likely gonna use 4 awg to send power to your amp. It makes sense to use the same gauge wire on the negative side. 
Originally Posted by Blahman2
Not at all true... The negative terminal on the battery is grounded to the chasis... So that idea is pointless. Will not work.
yes, it does help...that is my final answer! a grounding kit would also help...there's millions of threads on this topic...please search it up!!!
keep in mind people, electricity runs from negative to positive...NOT positive to negative...so technically, ur powering ur entire car with 1 negative wire from the battery, so upgrading this wire would mean more juice to the car...
Hi trust me adding a cap with help get rid of dimming. When i have rockford 1000bd pushing 2 hx2 12's. Everything in my car was dimming. I got a 2.4farad cap and i had no dimming. All this people that have cap in there aren't stupid. IT DOES WORK. About the BIG 3 i dont know what it did becasue now i have JL 1000/1 with 12w7 and a battery in the back, so i had no dimming,but i still did the BIG three.
Electric Boogaloo...
iTrader: (6)
Joined: Mar 2003
Posts: 4,457
Likes: 1
From: Want to play a game?
Rep Power: 328 Kickercivic. Caps do not always work for everyone. The big 3, battery, and alternators work, to an extent, regardless of vehicle. People will aregue until they are blue in the face if caps work. The best thing someone can do is to try one and see if it does anything for them. Don't be so boneheaded to say that they always work, when they don't in every case.
Registered!!
Joined: Nov 2002
Posts: 30
Likes: 0
From: Prince Albert, Saskatchewan, Canada
Rep Power: 0 Caps do help for sure but grounds are the most vital part of any sound system. Think of power like a loop. Runs from battery to amp and back to battery. If you run 4 gu to amp but only 8gu back to battery its the same as ony 8gu to amp. Can cause noise overheated amps and in severe cases melted wires.
Originally Posted by PopcornPlaya
Kickercivic. Caps do not always work for everyone. The big 3, battery, and alternators work, to an extent, regardless of vehicle. People will aregue until they are blue in the face if caps work. The best thing someone can do is to try one and see if it does anything for them. Don't be so boneheaded to say that they always work, when they don't in every case.
. You are the only one that i came across that says it will do notting. It is meant for something. It give instant power to your amp which power wire coming straight from you battery all the way to the back wont provide. 
Joined: Sep 2002
Posts: 51,241
Likes: 20
From: NV
Rep Power: 812 maybe but you could get a voltage regulator like HVS or apexi and hook that to the battery. Either way these aren't gonna do much with a high draw that subs need. The alternator just can't put out enough, and when that happens the battery gets drained next. That's why an optima yellow battery is good cause it can get drained and recharged without damage. Just don't crank your system ALL the time.
Joined: Dec 2003
Posts: 4,773
Likes: 0
From: IL
Rep Power: 320 
my amp is never pushed to much more than half, and if u recall... I have an optima 
and my 1 farad cap.
I have a voltage meter on my radar and it doesnt fluctuate THAT much, it does sometimes, but like I said I dont crank the sub that much, mostly the just the speakers..
and my 1 farad cap.I have a voltage meter on my radar and it doesnt fluctuate THAT much, it does sometimes, but like I said I dont crank the sub that much, mostly the just the speakers..
^sounds like your running a quite serious system. you should've went the alternator route since you plan to slam your system. whats ur setup?
back to topic: are there any downfalls to connect the negative battery terminal to a car chassis? does it have to be a factory ground point as well or can u find a diff. spot on the car?
i was thinking of neg battery terminal > radiator support (additional ground that)
back to topic: are there any downfalls to connect the negative battery terminal to a car chassis? does it have to be a factory ground point as well or can u find a diff. spot on the car?
i was thinking of neg battery terminal > radiator support (additional ground that)
Joined: Sep 2002
Posts: 51,241
Likes: 20
From: NV
Rep Power: 812 Just use the factory points. They're already there so it's easier. You only need to run cables from battery negative to chassis, tranny, and engine block.
Electric Boogaloo...
iTrader: (6)
Joined: Mar 2003
Posts: 4,457
Likes: 1
From: Want to play a game?
Rep Power: 328
Originally Posted by kickercivic1
Every time i drive i have my system cranked. I have 2 battery and a 2.4f cap.
OK so you prove me wrong that it doesnt . You are the only one that i came across that says it will do notting. It is meant for something. It give instant power to your amp which power wire coming straight from you battery all the way to the back wont provide.
when i had my 800watt system, i had a 1 fared cap and no dimming at all.
now im running 500 watts and no cap, i have minor dim when the bass hits hard. not a biggie, but still noticeable if im slamming my system.
from my expierence, the 1 farad cap helped my dimming for me.
id be pretty pissed if a cap didnt help dimming when thats what there invented for
now im running 500 watts and no cap, i have minor dim when the bass hits hard. not a biggie, but still noticeable if im slamming my system.
from my expierence, the 1 farad cap helped my dimming for me.
id be pretty pissed if a cap didnt help dimming when thats what there invented for
Electric Boogaloo...
iTrader: (6)
Joined: Mar 2003
Posts: 4,457
Likes: 1
From: Want to play a game?
Rep Power: 328 I'd be pissed too, but unfortunately, that's some people's experiance with them. Just make sure, when buying a cap, that you check for good capitence, as that and not the farad number is what's going to matter. Personally, I'd go with a battery and upgrading the wiring first then maybe a cap, and alternator last (as that's the most cost effective way I'd guess). The battery and upgrading grounds will do more than the cap would, but still, if you wat one, make sure of it's capitence rating.
Registered!!
Joined: Jul 2004
Posts: 120
Likes: 1
From: Fairfield County, CT
Rep Power: 0 
I am a certified mobile entertainment installer, and have found that a cap does not always do the trick. The most important thing a cap does is relieve the strain on the car's electrical system for this quick hits. I always recommend a cap and upgrading the grounding.
^well i was always told by my buddy who's an installer that a cap is more like an extra battery....it'll drain from the cap first before draining from the battery...which is good so it doesn't drain ur car's battery if ur alternator isn't pushing out enough juice...but still is bad cause u'll eventually run out of power
Electric Boogaloo...
iTrader: (6)
Joined: Mar 2003
Posts: 4,457
Likes: 1
From: Want to play a game?
Rep Power: 328
Originally Posted by kickercivic1
if you know.. Then post the charts or specs or something that is legit? stop telling people it will not help because it didnt work for you.
Here's a few threads, where plenty of knowledge is dropped:
http://www.7thgencivic.com/forums/sh...=102957&page=2
http://www.7thgencivic.com/forums/sh...&highlight=cap
http://www.7thgencivic.com/forums/sh...&highlight=cap
There's a better thread that discusses caps in further detail. Hell, I've linked to it before. It's about 4pages long, and several people were owned in it by Ludlam. Try to find it.
As for Richard Clark, yo can find him here:
www.forums.elitecaraudio.com
