DIY Big 3 Wiring Upgrade Kit

[Taylor20]

So the wire from the alternator the battery does not have a fuse in it? The wire is connected directly from the battery to the alternator? If so, that is potentially a problem. Toyota fused the alternator cable to protect the alternator (primarily) as well as the rest of the circuits. If you happen to connect the jumper cables backwards on a cold night, your alternator will fry instantly since there is no fuse to blow.

It looks like from your instructions you are removing the original cable from the fuse box to the alternator. That is good, and what I have been recommending. That removes the 'dual circuit' paths, and will keep the wire from the battery to the alternator from feeding back into the fuse box downstream of the 120 amp fuse. However, without a fuse in the line from the battery to the alternator, there is nothing to protect the alternator, or the battery if the alternator shorts out.

I fully understand your statement(s). So if one wants to add a wire directly from the alternator to the battery, they could add a 120 amp or whatever circuit breaker, from Stinger for example, in that wire to resolve this issue. If one is installed, and lets say jumper cables are installed incorrectly, the circuit breaker would pop, saving one from a potential problem. All that would be needed to do is reset the breaker and they should be good to go.

 

[Doc2012]

Here's where I'm confused, and no disrespect meant at all [MENTION=59733]98OzarksRunner[/MENTION].

People with winches, lights, stereos, ect ect, have been doing "The Big 3" for years, and not one person has had a single issue out if it.

That means that something in the system is working right, and that this upgrade works.

If there were an issue with doing "the big 3", someone, somewhere, would have reported it.

Thank you for the email. I really do mean that.

You make some valid points. But I still feel that there is something not right. I've been running the "3" for a while.

Going straight from the alt to the battery is the way to go. You can't add to the fuse box, the wire is too small and the spot the wire goes to is just too small. Going directly to the battery is the best bet.

Again, no disrespect meant. But something in the "3" is working, and not causing any problems.
[MENTION=99491]Bumper2Bumper Auto[/MENTION]

The CS144 requires no modification either, unless you want to try and find a pulley that fits and is the same as a Toyota pulley. A spacer is placed behind the alternator, 3 washers, and there is a pigtail that allows you to connect the CS144 to the stock wiring. Plug and play.

 

[Bumper2Bumper Auto]

So the wire from the alternator the battery does not have a fuse in it? The wire is connected directly from the battery to the alternator? If so, that is potentially a problem. Toyota fused the alternator cable to protect the alternator (primarily) as well as the rest of the circuits. If you happen to connect the jumper cables backwards on a cold night, your alternator will fry instantly since there is no fuse to blow.

It looks like from your instructions you are removing the original cable from the fuse box to the alternator. That is good, and what I have been recommending. That removes the 'dual circuit' paths, and will keep the wire from the battery to the alternator from feeding back into the fuse box downstream of the 120 amp fuse. However, without a fuse in the line from the battery to the alternator, there is nothing to protect the alternator, or the battery if the alternator shorts out.

Yes, the cable from the alternator goes directly to the battery. Vehicles have been doing this for decades with no problem. The alternator "fuse" in the fuse block is not simply there to protect the alternator. It is the primary fuse for the VEHICLE, and is there to prevent the electrical harness from catching fire and or melting in the chassis if there were a major short at the fuse box. Running the alternator charge cable straight to the battery is common in MANY vehicles today still, and they have no problems with it being connected this way. Toyota simply has a huge fuse that they added to the alternator in the case of a short in the electrical system.

Considering how short the alternator cable is, and the way it is routed, it is not going to short out on it's own. The insulation is quite thick, and it would take a full frontal collision to have a chance to short out this cable. If that were to happen then the battery itself would have already been destroyed, and there would be more problems than just a shorted cable. As I said, many manufacturers have been doing the cable this same way for decades, and still do. There is no danger in the way my system is wired.

So what does the big 3 wiring upgrade actually do?

The factory battery and alternator cables are typically small gauge cables, especially on the older generation trucks. They are as small as 8 gauge. When you are looking at adding a winch and/or a high power amp, many people want to get a larger alternator. Since a larger alternator is capable of much higher of an output than the stock alternator, larger, stronger cables are needed to carry this extra current when it is in demand. The "Big 3" as it is commonly called replaces the battery to starter cable, battery to engine block cable, and battery to alternator cable. (My kit also replaces the battery to fuse block cable, as well as the battery to left fender body ground)

Here's where I'm confused, and no disrespect meant at all [MENTION=59733]98OzarksRunner[/MENTION].

People with winches, lights, stereos, ect ect, have been doing "The Big 3" for years, and not one person has had a single issue out if it.

That means that something in the system is working right, and that this upgrade works.

If there were an issue with doing "the big 3", someone, somewhere, would have reported it.

Thank you for the email. I really do mean that.

You make some valid points. But I still feel that there is something not right. I've been running the "3" for a while.

Going straight from the alt to the battery is the way to go. You can't add to the fuse box, the wire is too small and the spot the wire goes to is just too small. Going directly to the battery is the best bet.

Again, no disrespect meant. But something in the "3" is working, and not causing any problems.
[MENTION=99491]Bumper2Bumper Auto[/MENTION]

The CS144 requires no modification either, unless you want to try and find a pulley that fits and is the same as a Toyota pulley. A spacer is placed behind the alternator, 3 washers, and there is a pigtail that allows you to connect the CS144 to the stock wiring. Plug and play.

When I mentioned "no modification" I meant that the alternators I sell are a direct fit, meaning no issues with pulleys, spacers, or a pigtail. Mine bolt in exactly like the factory alternators, because their wiring and chassis ARE factory. So since you have a pigtail and spacers to deal with, I consider that "modified" in my opinion. That is what I meant. I know that the CS144 is a good alternator, but at idle the output still isn't as high as it should be. The CS144 is only rated to 80A at idle speed. My 130A alternator is rated at 91A at idle, and typically costs less.

Now Doc, you did put in a CS144 with your upgrade, right? I have always been curious how that looked and how easy it was to install.

 

[Doc2012]

Now Doc, you did put in a CS144 with your upgrade, right? I have always been curious how that looked and how easy it was to install.

Just busting your ass man. I guess there is some "modifying", but nothing crazy. Maybe 31 bucks worth with the harness and the washers.

Installing the CS144 was a breeze. Couldn't have gone any smoother.

The bolt holes line right up, the only thing you need to do is have the washers. Put them on the back of the alternator, on the top bolt, and tighten it up. It's about 3/8-1/2" difference. Nothing major.

NOW, I did mine differently. I HAD to get my truck running, was my DD at the time and had to be at work the next day, so I spliced the CS144 pigtail into the stock harness. If I could do it again, I'd just get the adaptor harness.

Here's the link.

http://www.toyota-4runner.org/3rd-gen-t4rs/135318-docs-cs144-alternator-upgrade.html


EDITED TO ADD:


I did the CS144 LONG before I did "The Big 3". Had no issues on the stock wiring with the CS144.

 

[98OzarksRunner]

Here's where I'm confused, and no disrespect meant at all [MENTION=59733]98OzarksRunner[/MENTION].

People with winches, lights, stereos, ect ect, have been doing "The Big 3" for years, and not one person has had a single issue out if it.

That means that something in the system is working right, and that this upgrade works.

If there were an issue with doing "the big 3", someone, somewhere, would have reported it.

Thank you for the email. I really do mean that.

You make some valid points. But I still feel that there is something not right. I've been running the "3" for a while.

Going straight from the alt to the battery is the way to go. You can't add to the fuse box, the wire is too small and the spot the wire goes to is just too small. Going directly to the battery is the best bet.

Again, no disrespect meant. But something in the "3" is working, and not causing any problems.
[MENTION=99491]Bumper2Bumper Auto[/MENTION]

The CS144 requires no modification either, unless you want to try and find a pulley that fits and is the same as a Toyota pulley. A spacer is placed behind the alternator, 3 washers, and there is a pigtail that allows you to connect the CS144 to the stock wiring. Plug and play.

No problem, and no disrespect intended here either. However, as I noted earlier, the Big 3 really doesn't add any capability or more power. If you have a CS144, the larger wire might allow for more current from the alternator to the battery than the stock wiring before causing a minor voltage drop, but the difference would be very minor, and only when the truck was running and an extremely high current load was on it - like a winch. But even then, the limiting factor is not the wiring, but the capacity of the alternator. The stock wiring should handle all the current a CS144 is capable of supplying, though I might change the 120 amp fuse to a 150 (probably still within the rating of the factory wiring). The big 3 won't charge your battery faster or supply more current than the factory wiring (since the factory wiring isn't the limiting factory - the alternator is). It looks good, but the factory wiring should be more than sufficient even for a CS144. The extra current the winch requires (beyond what the alternator can supply) will come from the battery, and won't go through the new heavier wire. The upgrade might 'work' but that doesn't mean there is any real benefit from it.

However, if you have a 200 amp alternator, I'd upgrade to the heavier cable from the battery to the alternator, with a larger fuse, but disconnect the original alternator wiring from the fuse box (and a larger ground cable too).

But doing the big 3 introduces a potential safety issue. Just because nobody has had any problems yet doesn't mean that it won't, much less, can't happen to somebody. Install the battery terminals backwards, or jump start a low battery and get the cables backwards and the difference between blowing the fuse at 120 amps and 240 amps is likely to be a very hot set of jumper cables, and a fried alternator. Get in an accident that shorts the cables or alternator to ground and it might start a fire. It won't cause any problems under normal circumstances, because unless there is a short, the rating of the wire, or alternator diodes, will never be exceeded. But fuses aren't there to protect the components and wiring when everything is working; they are there to protect things when something goes wrong. (And yes I know the cable to the starter is unfused and can be shorted in an accident.)

It's really very basic electronics - 2 circuits in parallel split the current between them based on their relative resistances. In this case there are two current paths (the original wiring through the fuse box to the alternator and the new wire from the battery to the alternator) that are of approximately equal resistance. Thus it will take 240 amps (in theory) for either fuse to blow, and that is twice the current rating of the original design. Removing the original wire from the fuse box to the alternator (as the Tacoma World kit does) solves this part of the problem since it removes the second (original) current path (but with their kit there is now an unfused cable from the battery to the alternator, which pretty much guarantees a fried alternator if you get the jumper cables backwards).

Given that hundreds of thousands of 4Runners have done just fine with the factory wiring, unless you have a dual battery system (which will require more rewiring than this) the factory wiring will do just fine. Again, if you have accessories, power them directly from the battery through an auxiliary fuse panel. It's safer, easier, and will do a better job of it.

 

[IBallEngineer]

no additional current is going through the wire to (or from) the alternator even when the winch is running[/COLOR].

The best upgrade would be to add a Blue Sea fuse panel and run all the aux wiring through it (lights, HAM radio, etc.) as I did. Run a #4 wire to it and upgrade the ground wire, and you've accomplished more than the big 3, is much easier to do, and more effective at powering your accessories (and won't burn down your truck should you ever get a short in the alternator).

I hate to keep doing this,:deadhorse: but this is just wrong. When you are running the winch, you are pulling down the battery in a way even the alternator could not sustain for very long. So to say no additional current is going to or from the alternator is 100% false. The battery voltage would drop, thus drawing more current from the alternator. I use a hydraulic winch so I can't demonstrate this for you, but in a real world test I have had an inductive ammeter on the wire from the alternator with 12 55w lamps, all headlights on and 2 10" HID Spotlights and I max the alternator output of 85-95 Amps.

Obviously the winch wouldn't run for extended periods, but the amperage draw from the battery must be replaced by the alternator.

 

[Bumper2Bumper Auto]

Just busting your ass man. I guess there is some "modifying", but nothing crazy. Maybe 31 bucks worth with the harness and the washers.

Installing the CS144 was a breeze. Couldn't have gone any smoother.

The bolt holes line right up, the only thing you need to do is have the washers. Put them on the back of the alternator, on the top bolt, and tighten it up. It's about 3/8-1/2" difference. Nothing major.

NOW, I did mine differently. I HAD to get my truck running, was my DD at the time and had to be at work the next day, so I spliced the CS144 pigtail into the stock harness. If I could do it again, I'd just get the adaptor harness.

Here's the link.

http://www.toyota-4runner.org/3rd-gen-t4rs/135318-docs-cs144-alternator-upgrade.html


EDITED TO ADD:


I did the CS144 LONG before I did "The Big 3". Had no issues on the stock wiring with the CS144.

I wasn't thinking you were insulting me or anything, no worries. I was just curious as I had heard that the CS144 had to have a new pulley and other things done, so I didn't consider it a true "plug and play" system. It does seem pretty easy to install, but I don't like the output rating at idle.

No problem, and no disrespect intended here either. However, as I noted earlier, the Big 3 really doesn't add any capability or more power. If you have a CS144, the larger wire might allow for more current from the alternator to the battery than the stock wiring before causing a minor voltage drop, but the difference would be very minor, and only when the truck was running and an extremely high current load was on it - like a winch. But even then, the limiting factor is not the wiring, but the capacity of the alternator. The stock wiring should handle all the current a CS144 is capable of supplying, though I might change the 120 amp fuse to a 150 (probably still within the rating of the factory wiring). The big 3 won't charge your battery faster or supply more current than the factory wiring (since the factory wiring isn't the limiting factory - the alternator is). It looks good, but the factory wiring should be more than sufficient even for a CS144. The extra current the winch requires (beyond what the alternator can supply) will come from the battery, and won't go through the new heavier wire. The upgrade might 'work' but that doesn't mean there is any real benefit from it.

However, if you have a 200 amp alternator, I'd upgrade to the heavier cable from the battery to the alternator, with a larger fuse, but disconnect the original alternator wiring from the fuse box (and a larger ground cable too).

But doing the big 3 introduces a potential safety issue. Just because nobody has had any problems yet doesn't mean that it won't, much less, can't happen to somebody. Install the battery terminals backwards, or jump start a low battery and get the cables backwards and the difference between blowing the fuse at 120 amps and 240 amps is likely to be a very hot set of jumper cables, and a fried alternator. Get in an accident that shorts the cables or alternator to ground and it might start a fire. It won't cause any problems under normal circumstances, because unless there is a short, the rating of the wire, or alternator diodes, will never be exceeded. But fuses aren't there to protect the components and wiring when everything is working; they are there to protect things when something goes wrong. (And yes I know the cable to the starter is unfused and can be shorted in an accident.)

It's really very basic electronics - 2 circuits in parallel split the current between them based on their relative resistances. In this case there are two current paths (the original wiring through the fuse box to the alternator and the new wire from the battery to the alternator) that are of approximately equal resistance. Thus it will take 240 amps (in theory) for either fuse to blow, and that is twice the current rating of the original design. Removing the original wire from the fuse box to the alternator (as the Tacoma World kit does) solves this part of the problem since it removes the second (original) current path (but with their kit there is now an unfused cable from the battery to the alternator, which pretty much guarantees a fried alternator if you get the jumper cables backwards).

Given that hundreds of thousands of 4Runners have done just fine with the factory wiring, unless you have a dual battery system (which will require more rewiring than this) the factory wiring will do just fine. Again, if you have accessories, power them directly from the battery through an auxiliary fuse panel. It's safer, easier, and will do a better job of it.

I think you are misunderstanding the purpose of my Kits, and the basis for the "Big 3" when it comes to my system. My system, as mentioned, is a stepping stone for those who plan to get into larger alternator systems, and to run them with stereo systems and winches. I offer several different Kits for single, dual, high capacity, Self-starting, and solar systems. The Stage 1 Kit is the first step. You don't want to install a high output alternator, THEN upgrade the cables later. That is like putting the cart before the horse. My kits are for those who are already planning to get a higher output alternator. The factory cable for the alternator is only 6 gauge. A 6 gauge cable is rated for 2.6% voltage loss over 3 feet. (average alt cable length for Tacoma) When planning for just a simple 130A upgraded alternator, the current requirements for the cable show that 6 gauge will work, but is at the limit. I don't like playing with electricity at it's "limit".

Stepping up to the more common alternator rated at 200A, which has an idle output of 140A, which is great for the high power amplifiers, stereos, or heavy offroad lighting (Continuous draw) will necessitate 4 gauge cable. Thus the need for the upgraded wiring kit. That is the reason I build and sell these kits: Not for a simple replacement, but for a stepping stone for much larger upgrades in the electrical system.

And again, there are thousands of trucks and cars out there that have the same direct connection to the battery as my system does, and none of THEM catch fire or blow up alternators if someone accidentally connects the cables wrong. It is not the alternator at risk in the first place. with an alternator that is not turning, the direction of current connected is irrelevant, because the diodes in the alternator prevent reverse voltage from passing through the alternator in the first place. (Try it some time. We have when going over automotive electronics. Connecting 12 volts in reverse polarity to an alternator did absolutely no damage to the alternator at all.) The fuse blows to protect the rest of your vehicle's electrical components. And when you install my Kits per instruction, those same circuits are protected with the same factory fuses.

 

[98OzarksRunner]

I hate to keep doing this,:deadhorse: but this is just wrong. When you are running the winch, you are pulling down the battery in a way even the alternator could not sustain for very long. So to say no additional current is going to or from the alternator is 100% false. The battery voltage would drop, thus drawing more current from the alternator. I use a hydraulic winch so I can't demonstrate this for you, but in a real world test I have had an inductive ammeter on the wire from the alternator with 12 55w lamps, all headlights on and 2 10" HID Spotlights and I max the alternator output of 85-95 Amps.

Obviously the winch wouldn't run for extended periods, but the amperage draw from the battery must be replaced by the alternator.

My point is that the alternator will max out at 85-95 amps (or whatever it can supply), and then the difference comes from the battery (the primary draw will come from the alternator since it will supply all it can to keep the battery voltage up, so in reality the additional current doesn't come from the alternator, but from the battery). No additional current (as in more than it is able to supply) is coming from the alternator, and if the stock wiring can handle as much current as the alternator CAN supply, there is no need to increase the wire size.

 

[IBallEngineer]

My point is that the alternator will max out at 85-95 amps (or whatever it can supply), and then the difference comes from the battery (the primary draw will come from the alternator since it will supply all it can to keep the battery voltage up, so in reality the additional current doesn't come from the alternator, but from the battery). No additional current (as in more than it is able to supply) is coming from the alternator, and if the stock wiring can handle as much current as the alternator CAN supply, there is no need to increase the wire size.

OK, so your vernacular confused what you were saying earlier. AND I almost agree with you. Remember I said the big 3 is much about almost nothing, well I think for almost everyone that is true. Two contrary views that both have legitimacy are at work here.

1. Toyota builds a quality product that works well as is.

2. Manufactures build to a minimum acceptable standard to keep costs down.

Both are true, and we have to keep both in mind when deciding to become backyard engineers. Many of us have a lot of training, and/or years of experience to draw from and have formed conclusions we are loathe to be moved from. Today I will grudgingly move slightly in your direction. From now on I will recommend the big 3 eliminate the redundant charge circuit. Not because I fear burning Toyotas, but because it is redundant, and can confuse future trouble shooting. However because I love a good electrical circuit, I will still say the big 3 is worth doing under the right circumstances. Those being any of the following.

Additional battery
Higher amperage alternator
Poorly maintained OEM cables.

I remember when the big 3 were Ford, GM, and Chrysler!

eace:

 

[98OzarksRunner]

OK, so your vernacular confused what you were saying earlier. AND I almost agree with you. Remember I said the big 3 is much about almost nothing, well I think for almost everyone that is true. Two contrary views that both have legitimacy are at work here.

1. Toyota builds a quality product that works well as is.

2. Manufactures build to a minimum acceptable standard to keep costs down.

Both are true, and we have to keep both in mind when deciding to become backyard engineers. Many of us have a lot of training, and/or years of experience to draw from and have formed conclusions we are loathe to be moved from. Today I will grudgingly move slightly in your direction. From now on I will recommend the big 3 eliminate the redundant charge circuit. Not because I fear burning Toyotas, but because it is redundant, and can confuse future trouble shooting. However because I love a good electrical circuit, I will still say the big 3 is worth doing under the right circumstances. Those being any of the following.

Additional battery
Higher amperage alternator
Poorly maintained OEM cables.

I remember when the big 3 were Ford, GM, and Chrysler!

eace:

Agreed.eace:

 

[BrianSD_42]

The reason why I left the factory wiring in place when I did the big three is because I wasn't convince a car audio Copper Clad Aluminum 4G (not to be confused with 4AWG) cable was even as heavy duty as the factory wire which appears to be real copper and although physically thinner, actually heavier thicker metal strands. For that reason I used the big3 to supplement the factory wiring and added the breaker same as BigFishAllDay.

 

[Bumper2Bumper Auto]

Looks like everyone has very valid points to make. Good to see a conversation that does not slide into name calling. Enjoy everyone! And again, if there are any questions on my systems, feel free to ask!
:hippie:

 

[infamousRNR]

so with all that said and done by everyone.....

- with running extra lights (light bar, additional aux lighting on roof rack, back up lights etc)
- a winch
- a 1000w subwoofer system with additional 400w going to speakers ( or any kind of system exceeding 1000w)
- a power inverter
- an ARB fridge
- an extra battery
- air compressor
- and anything else you can strap to your vehicle that would draw additional current


is everyone agreeing that it DOES help or DOES NOT help?......


to put it in the most basic form...

if you have a hose with water running through it... and you turn up the amount of water through.. wouldn't it be LESS stress on the hose to have a wider hose?...

or in this case a wire that provides MORE current?.... (like a 4, 2 or 0 gauge wire)

isn't that what the big 3 is doing? allowing more current to run to your addition; accessories?


i wanted to do the big 3 and bought everything for it...

but now I'm just as confused as ever...

of course by skipping the factory wiring you WILL need a fuse running from the positive (+) battery terminal to the alternator...

can we wake this thread up again with pictures of peoples big 3 and real life experience after doing this mod and see what the effects have been? positive or negative?

and do we ADD to the existing wiring or REPLACE the existing wiring?.,,,

 

[T4Rfirefighter]

infamousRNR, I'm just as confused as you after reading this thread. I've done the Big 3 on several vehicles I've owned in the past, and with some I replaced wiring, while I added to stock wiring on others.

I can tell you from my experience as a firefighter that your logic on hydraulic pressure and friction loss is correct, but I am not nearly as familiar with electricity and have just as many questions as you do on this.

I hope somebody can clear this up without it turning into bickering about who is right.

 

[infamousRNR]

Big 3..4

[MENTION=96877]T4Rfirefighter[/MENTION] glad to see someone else wants a little closure on this...

So does anyone have any pictures to post of their big 3 or big 4?...

And their experience with haven't installed it and running it for a little while?...

 

[4Running Daily]

[MENTION=96877]T4Rfirefighter[/MENTION] glad to see someone else wants a little closure on this...

So does anyone have any pictures to post of their big 3 or big 4?...

And their experience with haven't installed it and running it for a little while?...

No pictures... But I am up to 14.3 running volts. I think the Big 3 Upgrade is worth doing, however if you put the big 3 upgrade relative to lets say running a winch, I doubt you'll see a very noticeable difference. A larger Alternator, or a Battery with more CCA's would net you more of a noticeable gain when it comes to a load.

 

[hour]

For the one drive that I took in my 4runner post-CS144 upgrade, I was exceeding 14 volts more often than not. Same conditions (lights off or on, same song, same volume, same sub amp settings) I was dropping to mid 11's during extended bass hits. I would have done more testing but my freaking new alternator tensioner bolt broke.

I have the parts for the big 3 and will do it once it stops snowing / snow on ground melts, but in my experience the upgraded alternator will help immensely.

For those not wanting to buy a kit, I found the Xscorpion terminal on Amazon and got for <$20. Got another one of similar style for the negative (no voltmeter) for $10 from Amazon as well. Battery cable @ Advance Auto Parts was $2/ft for 2 gauge. Listing doesn't say it's aluminum clad like many of their other wires and from visual inspection it seems to be 100% copper fine strand. It's rigid as hell though, going to be a pain routing it where it needs to go. Wanted welding cable like used in the kit mentioned but couldn't find it by the foot locally.

 

[T4Rfirefighter]

For the one drive that I took in my 4runner post-CS144 upgrade, I was exceeding 14 volts more often than not. Same conditions (lights off or on, same song, same volume, same sub amp settings) I was dropping to mid 11's during extended bass hits. I would have done more testing but my freaking new alternator tensioner bolt broke.

I have the parts for the big 3 and will do it once it stops snowing / snow on ground melts, but in my experience the upgraded alternator will help immensely.

For those not wanting to buy a kit, I found the Xscorpion terminal on Amazon and got for <$20. Got another one of similar style for the negative (no voltmeter) for $10 from Amazon as well. Battery cable @ Advance Auto Parts was $2/ft for 2 gauge. Listing doesn't say it's aluminum clad like many of their other wires and from visual inspection it seems to be 100% copper fine strand. It's rigid as hell though, going to be a pain routing it where it needs to go. Wanted welding cable like used in the kit mentioned but couldn't find it by the foot locally.

I've gotten all my welding cable off eBay through an electrical supply house in Michigan. The stuff is called Excelene and it is very flexible. Highly recommend it.

 

[Bandit Runner]

So I recently replaced my battery and I figured I would do the Big 3 upgrade while I was at it. Sadly, living in a dorm room, I couldn't build the wires myself because I have no tools. Luckily there is a man on Tacoma World that builds kits for 1st gen Tacoma's. So in this thread I will be posting photos of the kit and my install of it.

Information of kit:
Stage 1 consists of new positive and negative battery cables and terminals for an Optima, or heavy duty top-post battery. Stage 1 uses 2-gauge welding cable for the power cable to the starter, as well as the ground cable to the engine block. It also uses 4-gauge welding cable for the alternator, as well as the cable to the fuse block. All cables have soldered terminal ends, which are better than the factory crimp connections. The only ends that do not have soldered terminals are the ends that go to the heavy-duty battery terminals, which use a brass allen set-screw. These set-screw ends are quite common in the audio industry for battery terminals.

Link to kit:
1st Gen (and upcoming 2nd Gen) electrical system upgrade! - Tacoma World Forums

Hi man,

I bought this same wiring kit, and spent a few hours today just looking at how to go about installing it. You know, making sure I know where each wire connects to and the wire routing, etc.

So I figured out where all the new wires go, but I am not entirely sure what to do with the OEM wiring. There seems to be a wiring harness assembly for the OEM wires. The way I see it, there are three options with what to do with this OEM wire harness assembly:

1. Remove the OEM wiring harness altogether. Run the new wires in place of it.
2. Leave it in place, and just leave the OEM wires not connected to anything. Run the new wires next to it.
3. Try to disassemble the OEM wiring harness. Replace the OEM wires inside it with the new upgraded wires. Reassemble the wiring harness.

So what did you do with the OEM wiring harness? Any help would be greatly appreciated. Thanks.

 

[4Running Daily]

I believe I removed all the old wires completely and just ran the new stuff. Being 20 year old wires, the coating were showing their age.