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The Big 3 upgrade - Explanation and How-To

51K views 71 replies 31 participants last post by  Sailing_Faith 
#1 ·
---EDIT--- This was originally posted here https://www.the12volt.com/installbay/fo ... ?tid=73496 by DYohn --AstroWill

Definition: the "Big Three" upgrade means improving the current capacity of three cables: 1) alternator positive to battery positive, 2) battery negative to chassis, and 3) engine ground to chassis. Some people replace the factory wiring; others add additional cables to the factory wiring. This instruction is to add cables to existing OEM wiring.

Parts and Tools:

As a minimum, you will need to purchase the following:

• Sufficient length of high-strand count high capacity power cable.

- The length required differs for every vehicle. You can measure the length of the existing cables and buy the same length, or contact your dealer or a mechanic and ask, or sometimes you can look it up in a manufacturer's wiring book, or guess. If you guess, make sure you over-estimate and buy too much.

- High strand count cable is more flexible and more reliable than low-strand count cable. Never use solid-core wire in a moving vehicle as it will eventually break.

- The gauge of wire you need depends on the total current draw of your audio system, and/or the current generating capacity of your alternator. Never use smaller cable that you used to power your amps; never use smaller cable than what already exists in your vehicle; never use smaller cable than the generating capacity of your alternator; never use smaller than 4 AWG (it's just not worth the time to use anything smaller); if in doubt, always use higher gauge cable than you think you need. If you look at the Power and Ground charts and your amplifier current draw corresponds to 2 AWG cable, use no smaller than 2 AWG cable, and use 1/0 if you can.

• 6 ring terminals or lugs of the appropriate size for the cable chosen. Two of these need to be large enough to fit over your battery posts, or appropriately sized to bolt onto your existing battery terminals.

• 1/2" or 5/8" shrink tubing (or some other form of permanent electrical insulation. Tape is NOT recommended.)

• Cable ties (plastic zip ties.)

• Wire cutters large enough to handle the cable you choose.

• Crimpers large enough to handle the connectors you choose.

• Soldering iron or gun.

• Solder.

• Scotch brite and/or a small wire brush.

• Heat gun.

• Safety razor blade (or other tool for stripping cable).

• Heat gun (if using shrink tubing).

• Wrenches for removing bolts in your vehicle.

Procedure:

1. Make sure your engine is completely cool before beginning. Identify the three cables being replaced. Make sure you can reach both ends of all cables. NOTE: the engine block to chassis cable may be between the engine and the transmission, or connected to the transmission and the fire wall, and is often an un-insulated flat braid cable.

2. Determine the lengths of cable needed to reach between the three locations being upgraded. Be sure you measure with a flexible tape (a tape measure used for sewing works great) and record the total length along the path you intend to install the cable. You do not want your cables to be pulled tight between any two locations as things move and vibrate as you drive. Be sure to include at least 1 inch extra for slack. NOTE: there is no reason to copy the existing wiring layout in your vehicle unless you want to. Also, be sure that the path you choose does not follow or lay across anything that gets hot, like exhaust parts, or anything that must move, like throttle linkage.

3. Cut your new cable to the three proper lengths. NOTE: some people like to use red cable for positive and black cable for negative. Doing this is completely up to you and is nice, but not necessary. You can use cable with any color insulation you like.

4. Strip each end of all cables to the proper length for the terminal lugs being used. NOTE: after full insertion into the lug, a small "band" of bare wire is usually seen between the back of the lug and the beginning of the cable insulation.

5. Begin at any one end and insert the stripped cable into the lug. Make sure it is fully inserted. Crimp the connector to hold the wire in place. NOTE: crimping large cable can be difficult. The intention here is not to make the crimp the sole means of holding the wire, but only to make sure the lug does not slip around during the soldering phase. I do NOT recommend using hammers or pliers or vices to crimp the connector as over-crimping can break the strands of the cable, reducing the current carrying capacity. Do not over-crimp.

6. You may need to use a vise or some other set of "helping hands" to hold the cable while you solder it. Heat your soldering iron and place it on the connector (on the lug side) barrel. Hold a piece of solder against the tip of the iron and melt the solder into the strands of the cable. Use sufficient solder to fill the connector and completely cover all strands of the cable. NOTE: the lug will get hot and will burn you if you try to hold it. Also, if the insulation on the cable starts to melt, you are over-heating the cable and not paying attention to melting the solder into the cable. You do not need to try and melt the cable!

7. Repeat the above steps on each end of all three cables.

8. After the cables have completely cooled, cut a piece of shrink tubing long enough to cover the soldered barrel end of the lugs and reach about 1/2" onto the insulation of each cable end. Slide this over each lug and use a heat gun to recover the tubing in place.

9. Disconnect your battery, starting with the negative cable first then the positive cable. Discharge any caps you may have in the system.

10. Begin adding your new cables along side the existing ones. I usually begin with the alternator positive cable. Locate the output stud on your alternator and remove the nut. Slip the new cable onto the lug and replace the nut. There is no need to disturb the existing cabling. Route the new cable to the battery and position it to connect to the positive battery post (or connect it to the positive terminal on the OEM wiring) but do not connect the battery yet.

11. Secure the new cable in place by using cable ties every 6 to 8 inches. Secure the cable to cool non-moving parts!

12. Locate where the negative battery cable attaches to the vehicle chassis. Remove this bolt and the OEM battery cable, and clean the mounting area of the chassis using scotch brite and/or a wire brush. Make sure there is no dirt, rust, paint, undercoating, etc in this location. You want bright shiny metal. Connect both your new ground and the OEM ground back to the chassis. NOTE: Some people like to create a new ground location by drilling into the chassis and using a bolt with star lock washers for the new ground cable. Route this new cable back to the battery and position it to be attached, or connect it to the negative terminal. Do not reconnect the battery yet.

13. Secure the negative cable using cable ties every 6-8 inches. Again, don't tie it to anything that moves or that gets hot!

14. Disconnect the engine ground strap at both ends. Using the wire brush or scotch brite, clean both the engine block and the chassis as you did for the first ground strap.

15. Line up the lugs on both the OEM ground strap and your new ground cable, and use cable ties to secure them to each other. This is much easier to accomplish in your lap or on the floor than it is while lying under your car or hanging upside down in the engine compartment. Reinstall both cables at the same time using the factory bolts.

16. Double check to make sure all bolts are tight. Be careful not to over-tighten them as you don't want to strip anything! Also, on some factory alternators it is WAY too easy to twist off the positive output lug. If you break it off, well hell, you really wanted a high-output alternator anyway, right? It is also a good idea at this point to measure resistance of the new cables. Take an ohm reading between the battery end of the new ground cable and the engine block. It should read less than one ohm. Also check between the alternator bolt and the disconnected positive battery terminal, which should also be less than one ohm. If you read too high resistance, double check all connections and make sure you do not have something c**ked sideways or hanging loose.

NOTE: Realize that the "absolute ground" of the electrical system is not the battery negative terminal or the vehicle chassis, but is the case of the alternator itself. This is why perhaps the most important cable among the Big 3 is the engine ground strap, as this is what connects the alternator ground to the vehicle's chassis. Be certain the resistance between the alternator case (the engine block assuming the alternator is properly bolted to the engine) and the battery negative is minimized. (Thanks to the12volt for pointing this out!)

17. When you are sure you are done and anything in your system that you may have disconnected are re-connected, clean your battery posts and reconnect the positive battery terminal first, then the negative one.

18. Start your vehicle. Hopefully the engine starts. :) Examine the engine compartment and make sure none of your cables are getting hot or are vibrating or shaking around. If they are vibrating too much you may need to relocate them or use more cable ties. If you see smoke, immediately shut off the car and disconnect the battery. Seek help. :)

19. Assuming all looks good, take a voltage reading at your amplifier and ensure you read 13.8 (or higher) volts. This indicates a properly operating charging system.
 
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#3 ·
DaveAstro said:
nice write up, hopefully the next person that does this can take pics of their progress and add it to this..
I currently have 4AWG run for mine, but am upgrading to 1/0AWG at some point soon.
I have done my about a year ago, if anyone wants i can take some pics.
I did mine with 4 gauge which i had at the time.
 
#4 ·
Honestly, I really don't see the need for pictures. It's pretty straight forward. Battery + to Alternator +, Battery ground to chassis, Alternator case (or engine ground) to chassis, using the largest wire you can, but a minimum of 4gauge. You also need to make sure the runs are in the shortest routes.

This is not a requirement unless you have a very high output alternator. Napa recommends doing this for an alternator rated at 140amps or more. The reason behind that is the factory wiring will not handle it and might melt/catch fire.
 
#6 ·
Jboy2 said:
DaveAstro said:
nice write up, hopefully the next person that does this can take pics of their progress and add it to this..
I currently have 4AWG run for mine, but am upgrading to 1/0AWG at some point soon.
I have done my about a year ago, if anyone wants i can take some pics.
I did mine with 4 gauge which i had at the time.
Pics please. thank you sir!!
 
#7 ·
petergunz559 said:
Jboy2 said:
DaveAstro said:
nice write up, hopefully the next person that does this can take pics of their progress and add it to this..
I currently have 4AWG run for mine, but am upgrading to 1/0AWG at some point soon.
I have done my about a year ago, if anyone wants i can take some pics.
I did mine with 4 gauge which i had at the time.
Pics please. thank you sir!!
I am going to doing 02 Astro soon with 0awg i will post some pic's when i am done if it's ok with JaxSPL this is his thread.
 
#8 ·
JaxSPL said:
This is not a requirement unless you have a very high output alternator. Napa recommends doing this for an alternator rated at 140amps or more. The reason behind that is, the factory wiring can not handle it and might melt/catch fire.
Nice to mention the high-output Alt. part.
But with all the changes to the stock system, you forgot to put some kind of fuse in alternator charge wire.

There are safety termination set-ups within the charging lead wire in modern auto systems today.
If there isn't one, the potential from frying something electrical, to burning your ride down are greatly increased.

So between the cost of putting in a hi-current flowing fuse in the Alternator's
charge wire, Vs.to losing your ride are not comparable. It's just good insurance.

Having an Alt. go bad & overcharge is rare, but has & can happen.
I've got lucky, when it happened to me.
All I lost was a pair of new stock headlights with some of the headlight wiring.
(all stock, older carb'ed car.)

Now that's said; aside from not up-sizing alternator charge wire.
Up-grading the other cables mentioned & adding more grounds is still a good idea.

I've also found that also replacing the wire to the starter with a
larger cable can make things more reliable upon start-up.
 
#9 ·
Shoutin05 said:
Can anyone remember the length they used? I'm looking to use 1/0 wiring. I have 6 Fi BTL 18" subs with 2 Rockford Fosgate T15k amps that needs to get powered by several batteries, what batters should i go with?
I would go with a H/O alternator before wasting money on batteries. I work for MTX and the number one reason for dead high output amps like the TE1501D and TE4001D is because people think that using a bank of batteries is sufficient alone for high dB systems. Fact is, batteries are just storage. Once that storage starts to get depleted you will start stressing the mosfets in the amplifiers which WILL eventually fry the amp and can even send distortion through the woofers and cook your voicecoils.
Best way to think of a high output amplifier, is to think of it like a big water pump. Your batteries are water jugs and your alternator is the hose refilling the jugs. The pump (amp) will work fine if you run it off the water jugs (batteries), but those jugs are going to start to run out of water real quick...so you have to refill them with the hose (alternator). If your hose (alternator) cant keep up with refilling the water jugs (batteries), then your pump (amp) is going to start burning up because you're telling it to work just as hard with little to no water (current), which then burns up the pump (amp). Do you see it?
Our factory alternators only produce about 90-105 amps of current, approx. 85 of that gets used by your vehicles systems to run...which in the case of a 105 amp alternator only leaves you about 20 amps of current free to power your system without taxing the battery. Now most efficient class D, 1000 watt RMS monoblocks will use 90-100amps of current to produce that wattage. Do you see it?

Long story short...Buy an alternator big enough to power your system, and then add a few batteries to buffer. DC Power Inc makes a 390 amp alternator for our vans, and a 320 amp for a price equal to about 5 basic batteries.

If you want my recommendation for batteries, Optima Yellowtops. They last long (unlike Kinetiks), give the output needed, and are had for a fair price.
 
#10 ·
Zombie, you had everything good until you mentioned the Optima yellow tops. I will never, ever, own another one. The last one I had decided the have a hole melted at the bottom corner of the battery, on the positive side, the size of a quarter. Never again will I go through that.

But yea, HO alternator first. A stock alternator will only handle a couple batteries, efficiently.

Now for the question about length of wire to use. The best way to tell this is to use the shortest distance between the connections, but remain away from heat (engine, exhaust, etc) and moving parts (fan blades and such).

Crazedfox. the reason I did not mention a fuse in the alternator charge wire is, I don't use them. It is really, more or less, owners choice on this. I prefer not to use them, but somebody else may want to for safety considerations. I don't even have a fuse from front battery to rear battery bank. That is my preference though.

There is something that Mr.Singh is working on. I'm not sure if he found out his answer though, but I've heard it from quite a few other places. The Astro factory equipment will handle 16volt without any problems. I am not 100% on this yet, as I and reluctant to try it, but it seems sort of sound.

Upgrading the wire to the starter is a great addition. I think, but not positive, there is a fused wire that goes from the battery + to the starter. Without this wire the Astro/safari will not charge. If the fuse (inline) blows, again, the battery(ies) will not charge. Upgrading that wire will help out quite a bit.

My brain is just starting to wake up (not much sleep yet, woke up due to indigestion). I'll go through this topic from the beginning and answer everything I can from step 1.
 
#12 ·
Figured,
__I'd mention the fuse in the Alt. charge wire for those that just want to improve the DC flow for stock to semi-stock rides.

I always try to up-grade/improve my charging & starting system when I first get a vehicle.
So I know there won't be an issue with starting/charging, & it will perform all around better.
All because it's getting all the volts in all the correct place's. If not, any electric problems will surely show up afterwords.
 
#14 ·
JaxSPL said:
Definition: the "Big Three" upgrade means improving the current capacity of three cables: 1) alternator positive to battery positive, 2) battery negative to chassis, and 3) engine ground to chassis. Some people replace the factory wiring; others add additional cables to the factory wiring. This instruction is to add cables to existing OEM wiring.

Parts and Tools:

As a minimum, you will need to purchase the following:

• Sufficient length of high-strand count high capacity power cable.

- The length required differs for every vehicle. You can measure the length of the existing cables and buy the same length, or contact your dealer or a mechanic and ask, or sometimes you can look it up in a manufacturer's wiring book, or guess. If you guess, make sure you over-estimate and buy too much.

- High strand count cable is more flexible and more reliable than low-strand count cable. Never use solid-core wire in a moving vehicle as it will eventually break.

- The gauge of wire you need depends on the total current draw of your audio system, and/or the current generating capacity of your alternator. Never use smaller cable that you used to power your amps; never use smaller cable than what already exists in your vehicle; never use smaller cable than the generating capacity of your alternator; never use smaller than 4 AWG (it's just not worth the time to use anything smaller); if in doubt, always use higher gauge cable than you think you need. If you look at the Power and Ground charts and your amplifier current draw corresponds to 2 AWG cable, use no smaller than 2 AWG cable, and use 1/0 if you can.

• 6 ring terminals or lugs of the appropriate size for the cable chosen. Two of these need to be large enough to fit over your battery posts, or appropriately sized to bolt onto your existing battery terminals.

• 1/2" or 5/8" shrink tubing (or some other form of permanent electrical insulation. Tape is NOT recommended.)

• Cable ties (plastic zip ties.)

• Wire cutters large enough to handle the cable you choose.

• Crimpers large enough to handle the connectors you choose.

• Soldering iron or gun.

• Solder.

• Scotch brite and/or a small wire brush.

• Heat gun.

• Safety razor blade (or other tool for stripping cable).

• Heat gun (if using shrink tubing).

• Wrenches for removing bolts in your vehicle.

Procedure:

1. Make sure your engine is completely cool before beginning. Identify the three cables being replaced. Make sure you can reach both ends of all cables. NOTE: the engine block to chassis cable may be between the engine and the transmission, or connected to the transmission and the fire wall, and is often an un-insulated flat braid cable.

2. Determine the lengths of cable needed to reach between the three locations being upgraded. Be sure you measure with a flexible tape (a tape measure used for sewing works great) and record the total length along the path you intend to install the cable. You do not want your cables to be pulled tight between any two locations as things move and vibrate as you drive. Be sure to include at least 1 inch extra for slack. NOTE: there is no reason to copy the existing wiring layout in your vehicle unless you want to. Also, be sure that the path you choose does not follow or lay across anything that gets hot, like exhaust parts, or anything that must move, like throttle linkage.

3. Cut your new cable to the three proper lengths. NOTE: some people like to use red cable for positive and black cable for negative. Doing this is completely up to you and is nice, but not necessary. You can use cable with any color insulation you like.

4. Strip each end of all cables to the proper length for the terminal lugs being used. NOTE: after full insertion into the lug, a small "band" of bare wire is usually seen between the back of the lug and the beginning of the cable insulation.

5. Begin at any one end and insert the stripped cable into the lug. Make sure it is fully inserted. Crimp the connector to hold the wire in place. NOTE: crimping large cable can be difficult. The intention here is not to make the crimp the sole means of holding the wire, but only to make sure the lug does not slip around during the soldering phase. I do NOT recommend using hammers or pliers or vices to crimp the connector as over-crimping can break the strands of the cable, reducing the current carrying capacity. Do not over-crimp.

6. You may need to use a vise or some other set of "helping hands" to hold the cable while you solder it. Heat your soldering iron and place it on the connector (on the lug side) barrel. Hold a piece of solder against the tip of the iron and melt the solder into the strands of the cable. Use sufficient solder to fill the connector and completely cover all strands of the cable. NOTE: the lug will get hot and will burn you if you try to hold it. Also, if the insulation on the cable starts to melt, you are over-heating the cable and not paying attention to melting the solder into the cable. You do not need to try and melt the cable!

7. Repeat the above steps on each end of all three cables.

8. After the cables have completely cooled, cut a piece of shrink tubing long enough to cover the soldered barrel end of the lugs and reach about 1/2" onto the insulation of each cable end. Slide this over each lug and use a heat gun to recover the tubing in place.

9. Disconnect your battery, starting with the negative cable first then the positive cable. Discharge any caps you may have in the system.

10. Begin adding your new cables along side the existing ones. I usually begin with the alternator positive cable. Locate the output stud on your alternator and remove the nut. Slip the new cable onto the lug and replace the nut. There is no need to disturb the existing cabling. Route the new cable to the battery and position it to connect to the positive battery post (or connect it to the positive terminal on the OEM wiring) but do not connect the battery yet.

11. Secure the new cable in place by using cable ties every 6 to 8 inches. Secure the cable to cool non-moving parts!

12. Locate where the negative battery cable attaches to the vehicle chassis. Remove this bolt and the OEM battery cable, and clean the mounting area of the chassis using scotch brite and/or a wire brush. Make sure there is no dirt, rust, paint, undercoating, etc in this location. You want bright shiny metal. Connect both your new ground and the OEM ground back to the chassis. NOTE: Some people like to create a new ground location by drilling into the chassis and using a bolt with star lock washers for the new ground cable. Route this new cable back to the battery and position it to be attached, or connect it to the negative terminal. Do not reconnect the battery yet.

13. Secure the negative cable using cable ties every 6-8 inches. Again, don't tie it to anything that moves or that gets hot!

14. Disconnect the engine ground strap at both ends. Using the wire brush or scotch brite, clean both the engine block and the chassis as you did for the first ground strap.

15. Line up the lugs on both the OEM ground strap and your new ground cable, and use cable ties to secure them to each other. This is much easier to accomplish in your lap or on the floor than it is while lying under your car or hanging upside down in the engine compartment. Reinstall both cables at the same time using the factory bolts.

16. Double check to make sure all bolts are tight. Be careful not to over-tighten them as you don't want to strip anything! Also, on some factory alternators it is WAY too easy to twist off the positive output lug. If you break it off, well hell, you really wanted a high-output alternator anyway, right? It is also a good idea at this point to measure resistance of the new cables. Take an ohm reading between the battery end of the new ground cable and the engine block. It should read less than one ohm. Also check between the alternator bolt and the disconnected positive battery terminal, which should also be less than one ohm. If you read too high resistance, double check all connections and make sure you do not have something c**ked sideways or hanging loose.

NOTE: Realize that the "absolute ground" of the electrical system is not the battery negative terminal or the vehicle chassis, but is the case of the alternator itself. This is why perhaps the most important cable among the Big 3 is the engine ground strap, as this is what connects the alternator ground to the vehicle's chassis. Be certain the resistance between the alternator case (the engine block assuming the alternator is properly bolted to the engine) and the battery negative is minimized. (Thanks to the12volt for pointing this out!)

17. When you are sure you are done and anything in your system that you may have disconnected are re-connected, clean your battery posts and reconnect the positive battery terminal first, then the negative one.

18. Start your vehicle. Hopefully the engine starts. :) Examine the engine compartment and make sure none of your cables are getting hot or are vibrating or shaking around. If they are vibrating too much you may need to relocate them or use more cable ties. If you see smoke, immediately shut off the car and disconnect the battery. Seek help. :)

19. Assuming all looks good, take a voltage reading at your amplifier and ensure you read 13.8 (or higher) volts. This indicates a properly operating charging system.
Den-while surfing the net I found that a member with the user Astrozam did this upgrade yrs ago and in fact had documented links on the net that almost for word of word is the same as your post.

http://www.the12volt.com/installbay/for ... 6&KW=big+3

:shrug: My point is this upgrade seems to be around for a long,long,time.
 
#15 ·
Good,
__one Lump.

As for this upgrade.
Yeah, it's been around.
For ever-since there's someone looking to improve what-ever they get there hands on.
They'll be passing the Ol' baton of customization to the next.
 
#20 ·
I bolted my new ground wire directly to the alternator bracket.And i replaced the 8 gauge wire from the battery to the fuse box with a 4 awg wire it made a big difference with the headlights on and the AC on full it stays at 14.4 volts with stock alternator. :cheers:

 
#22 ·
Lumpy said:
Nice and clean, Bones. Engine as well as install.

That fuse/relay block above your battery...Is that OEM for your year or aftermarket?

Lumpy
The relay block is in mine too so that must be gen2 but what is that right over top the battery? pos cable on the firewall, big fuse?
 
#23 ·
Now I gotta be Mr Fire Marshal and ask about something, Mr Bones.

Your pics show one of those battery terminal extender things on the POS term of your battery.
No problem with that.

BUT

You've got some cable eyes attached on the BATT side of that adaptor and some on the OUTside of the adaptor.
Now let's say you, or some mechanic or fireman wants to disconnect the battery. As you remove the outside bolt
from that POS terminal, and allow that POS cable to to free, if it contacts bare metal, are you still connected
to POS via the other cable(s) on the BATT side of the adaptor?

Is that an arc welder waiting to happen?

Lumpy
 
#24 ·
Lumpy said:
Now I gotta be Mr Fire Marshal and ask about something, Mr Bones.

Your pics show one of those battery terminal extender things on the POS term of your battery.
No problem with that.

BUT

You've got some cable eyes attached on the BATT side of that adaptor and some on the OUTside of the adaptor.
Now let's say you, or some mechanic or fireman wants to disconnect the battery. As you remove the outside bolt
from that POS terminal, and allow that POS cable to to free, if it contacts bare metal, are you still connected
to POS via the other cable(s) on the BATT side of the adaptor?

Is that an arc welder waiting to happen?
Lumpy
The stinger battery terminal are used for separating car audio form the van 12v so if i want to disconnect the audio i can do so with out interrupting the vans power. now for the mechanic it just adds one more step for him to disconnect the battery and for fireman they have no mercy they will cut everything under the sun. When adding any after market parts to your battery the risk for a short go's up 30 to 40% people who want after market audio except that risk you just need to make sure the battery is tied down not left loose you should no problem's. P.S i been install car audio since 1985 and i haven't had any short's dealing with the battery in any system that i have installed over the years.
 
#25 ·
Mr Bones said:
The stinger battery terminal are used for separating car audio form the van 12v so if i want to disconnect the audio i can do so with out interrupting the vans power...
OK. But when you disconnect the audio power cable, is it still hot with + voltage or is it totally
dead and separate from any other veh + supply like ignition sense (for radio memory) or
headlamp sense (for audio gear lighting dim)?

Just want to be sure you don't kill yourself. And if you do, can I have your front leaf hangers?

Lumpy
 
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