Doc's thoughts on the "Big 3 Upgrade"

[Doc2012]

Forgive me for jumping around so much here.



After reading this over and over again, (http://www.toyota-4runner.org/3rd-g...wiring-ugrade-3rd-gen-toyota-4runner-how.html) I still can't seem to wrap my head around "adding" two wires, and replacing one.







Why not replace all three wires? Hell, why not replace ALL those wires?



I was Googleing the shit out of this today and tonight. (It's 1 AM here and I'm usually out by 1030) I found a Big 3 Kit at Crutchfield. I called and asked about it, and they said that their kit REPLACES all three wires.



I asked about upgrading fuses, relays, the whole nine, and he said that they haven't had any issues with it.



I also asked about replacing ALL the wires in that loom, including the starter wires. He said "Why not?"



According to 4Crawler, the starter draws at least 20 amps. Why not upgrade that wire as well? Risk of burning up the starter?



I studied my truck for about 15 minutes tonight. I have 5 wires coming off my battery right now, which I desperately need to fix, thinking Blue Sea Fuse box, but I KNOW I'm going to end up running a dual battery set up. My battery is on the frits, if I let it sit for more than a day I need to jump the truck off. Getting a new battery, so I minus well do this while I'm in there. There is one wire from the alt to the battery, a separate from the battery to the fuse box. Why not add a 120amp circuit breaker between the battery and the fuse box, protecting all the stuff in there from a surge? That would still allow the alt to put maximum amps to the battery, for when I have my winch, correct?



I'm running the CS144, which puts out 140 amps. No problems from the system, or using the stock wiring.



I guess my predicament is, I want the most out of my alternator, but I don't want to fry the system.





My thoughts are to use 1/0ga wire for the alternator to the battery, engine ground to the chassis, and the battery negative to the chassis, just like the Crutchfield kit uses. Use some 4ga for the starter. Keep the stock wiring from the battery to the fuse box, but add in a 120amp circuit breaker to protect the system.



Does this sound like a good idea?


Edit: by chassis I mean body.

 

[rideexileex]

Why do you need to upgrade the starter wire?? It's already a relatively short run wire, and is more than plenty for just starting the vehicle...

Amps and Wire Gauge - 12V Circuit

 

[BrianSD_42]

The reason for adding the wires and not replacing them is more related to electrical theory than anything else.

I actually think the stock main power wire which is solid copper (vs stranded copper clad aluminum found in most stereo kits) has lower resistance per foot than whatever you would probably replace it with.

The way bfad wrote it, by simply adding the alternate wires you are providing additional current paths. There really is no major negative.

But if you or someone replaced the wire entirely you could quite possibly increase the circuit resistance due to a low quality metal cable.

Just my thoughts.

 

[Xinirgi]

The reason for adding the wires and not replacing them is more related to electrical theory than anything else.

I actually think the stock main power wire which is solid copper (vs stranded copper clad aluminum found in most stereo kits) has lower resistance per foot than whatever you would probably replace it with.

The way bfad wrote it, by simply adding the alternate wires you are providing additional current paths. There really is no major negative.

But if you or someone replaced the wire entirely you could quite possibly increase the circuit resistance due to a low quality metal cable.

Just my thoughts.

Are you sure it's a solid single strand of copper wiring such as the type found in house wiring? I'm pretty sure no automotive manufacture does that due to the risk of solid wires breaking under vibration (moving vehicles vs non-moving houses/buildings)

 

[Singtoe]

I think that it is a waste of money.

Toyota engineers have figured out the amp load for the given wiring.

Now, if your starter is starting to crap out and draw more amps, it could over load the current wiring but that is because your starter is crapping out.

The alternator upgrade of 140 amps does you no good because the alternator fuse is maxed out at 100 amps.

The correct size wire for 140 amp load from the battery to the alternator (>5 feet) is 4 gauge. If you could do it in 2.5 feet then the wire can drop to 6 gauge.

If you wire the alternator directly to the battery then you do not need a 120 amp circuit breaker.

 

[BrianSD_42]

Upon further thought it may not be a solid sinlgle strand but it is definitely very thick solid copper , possibly multiple thick strands.

My point is it probably has higher current pass through than 4g stereo copper clad aluminum. Therefore don't pull the factory wiring, just add an additional path.

I noticed a serious difference after doing this mod.

I am still able to use my original factory alt. I run HIDs, stereo 800 W RMS etc with no issues. My battery used to die all the time after sitting for two days. I attribute this to a bad charge.

Now I haven't had a dead battery in over a year AND I am still running the same Optima Yellow Top I bought in 2010. The only difference is that I did the big 3.

 

[Skidmarcx]

In my opinion there is no need to upgrade the cable to the starter since nothing changes when you add accessories unless you go through the trouble of wiring them from the starter... if you fry a starter cable there are issues that need to be resolved. Leaving the factory cables in place is less work and perfectly fine. I'd add a FUSED circuit from you alternator to B+ since the factory circuit is equipped with a 100 amp fuse. Upgrade B- to chassis and engine. From there it all depends on how you link your accessories to the battery whether it be directly or a remote fuse panel

 

[TheeMikeB]

I think that it is a waste of money.

Toyota engineers have figured out the amp load for the given wiring.

Now, if your starter is starting to crap out and draw more amps, it could over load the current wiring but that is because your starter is crapping out.

The alternator upgrade of 140 amps does you no good because the alternator fuse is maxed out at 100 amps.

The correct size wire for 140 amp load from the battery to the alternator (>5 feet) is 4 gauge. If you could do it in 2.5 feet then the wire can drop to 6 gauge.

If you wire the alternator directly to the battery then you do not need a 120 amp circuit breaker.

Are you saying you think the Big3 upgrade is a waste of money or spending money on the kit is a waste?

 

[BrianSD_42]

Well I've said that I'm skeptical if you need to do the entire big three. I did the whole thing and it worked but I just rushed into it.

I'd suggest the next person to try this just upgrade the battery negative to chassis wire to 4G as shown in my thread. Then if that doesn't improve things go through and do the rest of the upgrade.

 

[Nelsonmd]

Yeah, I would probably lean more towards replacing rather than adding more wires. You get better current flow through a single large wire than multiple smaller ones that form loops.

You do need to be careful about your crimped connections though, because you can easily make poor connections. I disagree with BFAD's method there. You should crimp first, then use flux cored solder to solder it after the crimp (or use a separate flux, just make sure it's electrical flux, not plumbing flux). Then cover in heat shrink, no need for the plastic covering.

You do also need to be careful about the wire you use, no CCA for this kind of stuff, be sure it's pure copper.

 

[LittleCaesar]

I'd have no problem doing the big 3 upgrade, but I would perform first a voltage drop test on both the starting and charging circuits. If they meet spec when using a DVM, I'd leave them alone, but if I were to replace one, I'm with Brian for at least replacing the ground off the battery:
Voltage Drop Testing