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The Big 3??

 

New member
Username: Bkoz

Post Number: 1
Registered: Feb-06
My lights dim when the bass from my subs hit and i want to upgrade my Alt. wires. Which wires do i need to upgrade? I seems that my battery has 2 grounds do i replace them both and do i need to remove all the old wires? Thanks!!! Please Help!!!!!
 

Bronze Member
Username: P_f_t

Post Number: 13
Registered: Feb-06
http://forum.sounddomain.com/ubb/ultimatebb.php?ubb=get_topic;f=5;t=007801
 

Bronze Member
Username: P_f_t

Post Number: 14
Registered: Feb-06
just copy paste it =P
 

Nanbakat
Unregistered guest
Here it is...(Copied and pasted)

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).

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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.

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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. If not, please don't hesitate to send me a PM.

--Chris
 

New member
Username: Bkoz

Post Number: 2
Registered: Feb-06
I have a Toyota Paseo and from my neg. battery post there is 2 wires coming off of it one is thinner then the other. Do I have to replace them both and Will 2 Gauge wire be good?? Thanks !!
 

Anonymous
 
all you need is a cap. the cap will solve all your problems. you can have as much amplifiers u want as long as you have a cap for each of them. your lights will not dim and your voltage will never drop.
 

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 11096
Registered: Dec-03
the big three, despite that whole cardomain thing, most times doesn't make any difference at all unless your car is old and has worn wires, or you've replaced the stock alternator with a high output model.
The big 3 swap can help a bit since factory wire isn't designed for sustained high current draw like you'll see from an audio system, but for the most part the factory wiring is sufficient for the peak output of the stock alternator.

a capacitor does absolutely nothing if you lack enough current for the amplifiers.. you need a HO alternator, and/or a second battery or bank of batteries, depending on if you need the power while the car is running, or shut off respectively.
Capacitors are useful as an AC ripple filter to smooth the DC voltage, and to reduce momentary propagation delay while waiting for teh alternator to respond with more current, but they will not, and I repeat NOT boost sagging voltage rails if the alternator is being overloaded.

more info here:
http://www.wickedcases.com/caraudio/capacitors.html
http://www.wickedcases.com/caraudio/charging.html
http://www.betteraudio.com/geolemon/newmain/battcapalt/
http://www.bcae1.com/charging.htm
http://www.bcae1.com/chargin2.htm
http://www.wickedcases.com/caraudio/batteries.html
http://www.the12volt.com/info/recwirsz.asp
 

Gold Member
Username: Bestmankind

Los Angeles, CA USA

Post Number: 2402
Registered: Oct-05
if you have the ho alt then why do you need an extra battery?
 

Silver Member
Username: Redliner

Wilmington, Ma

Post Number: 686
Registered: Jun-05
ya i asked that question before chad and someone just blew me off and called me retarted but i really want to know
 

Gold Member
Username: Bestmankind

Los Angeles, CA USA

Post Number: 2403
Registered: Oct-05
lol really charlie? i really don't know either. maybe glasswolf can tell us.
 

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 11098
Registered: Dec-03
it wasn't me, and I didn't see you ask. sorry about that. it is explained in the links I provided, but to give a brief answer, the alternator is the source of current for everything electrical in the car when the engine is running. The battery at any oint the engine is above idle RPM is in a charging state, or should be anyway, and acts only as a filter to help regulate the voltage the alternator produces, since your actual voltage regulator isn't perfectly smooth at turning AC to DC voltage.

The pupose of a second battery or battery bank is mainly for SPL competitors or people who run their stereo for long periods with the car turned off such as in competition lanes where by rule the car has to be off during metering and scoring. At that point high current stereo systems at high volumes will draw a lot of power, and the more and larger batteries you have connected in parallel and isolated for the audio system, the longer your runtime will be between periods where you need to start the car and give the alternator time to recharge the deepcycle batteries you use for the audio system.
deep cycles allow you to run the charge down to nearly zero volts without actually damaging the battery, whereas the typical lead acid starter battery will incur irreversible damage if it drops below about 9 to 10 volts.

did that help?
 

Silver Member
Username: Redliner

Wilmington, Ma

Post Number: 689
Registered: Jun-05
ya but what happens if you are going for a sq install and you dont run it while it is off is the ho alt and the battery sufficient thanks alot glass never new that
 

Silver Member
Username: Redliner

Wilmington, Ma

Post Number: 691
Registered: Jun-05
bump since it didnt
 

Silver Member
Username: N2audio

Lawrence, Ks USA

Post Number: 573
Registered: Mar-04
"all you need is a cap. the cap will solve all your problems. you can have as much amplifiers u want as long as you have a cap for each of them. your lights will not dim and your voltage will never drop."

You are retarded. Don't ever post in a car audio forum again.

You picked a good time not to log in.
 

Platinum Member
Username: Glasswolf

Wisteria, Lane USA

Post Number: 11117
Registered: Dec-03
if you mainly use the system when the car is running, the HO alternator is really what you want. the battery should be fine stock.
capacitor will help to smooth things out once the alternator is there, and the big 3 deal to handle the added current of the new alternator.
 

Gold Member
Username: Bestmankind

Los Angeles, CA USA

Post Number: 2411
Registered: Oct-05
lol optidriven. that guy is a retard. hopefully noone reads that and thinks he is right.
 

Silver Member
Username: N2audio

Lawrence, Ks USA

Post Number: 579
Registered: Mar-04
hopefully noone reads that and thinks he is right.
exactly the reason I replied.
 

Gold Member
Username: Carguy

Post Number: 5315
Registered: Nov-04
You don't need 2nd battery if you listen with engine running.
I have 2nd battery with isolator cause I prefer not to drain my starter battery during idle/stops.
 

Silver Member
Username: Redliner

Wilmington, Ma

Post Number: 729
Registered: Jun-05
ya great answer guys and ya that guy is definetly retarted biggest misperception in car audio
 

Silver Member
Username: Fandim

Reno, Nevada United State...

Post Number: 719
Registered: Jun-05
I have a 2nd and 3rd yellow top specifically for red lights. My alternator is a 200 amp alternator, and I'm running about 3kw RMS. My alt dosnt kick on until about 800-900 RPM, so one long red light, and I'll notice a SERIOUS dip in my voltage, even with a couple batteries, actually. I dont run them isolated, since I dont play my system with my car off.. it's specifically for just helping to regulate the voltage during times I may be idling, and dont want to be embarassed when my system shuts off from dropping below 11v.

Seth
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