Has anyone here upgraded the "Big 3" wires on their 4Runner? If you don't know, big 3 refers to the 3 major wires of the electrical system.
1) Battery negative to chassis
2) Alternator to battery positive
3) Chassis to engine

You replace them with a thicker cable, like 4 gauge, to get more power for your amps. Because I have light dimming problems (the headlights and indiglo gauges fade in and out when the sub hits hard) at idle with my current medium class amp and I was hoping to upgrade. I'd like to know if this is an easy upgrade, specifically for a 3rd gen 4Runner? Anyone have experience with this?

 

I did some of it on my 2nd gen, because the starter sounded awfully slow on cold mornings. If you want to actually replace the wires, it's not easy. I added another 4 ga from battery neg to frame because the factory one is sealed in the loom, and replaced the plenum-body ground with 4 ga. I could not get to the alternator + very easily so I didn't do that one, but probably should have. Seems like there should be another one from engine block to frame, but I couldn't find it.

How many Watts is your amp? I would check your amp grounds - they need to go to bare metal on the FRAME (not the body). I would add another healthy ground from the battery to bare metal on the frame, and one of 4crawler's headlight harnesses. If they still dim, I would look at adding a big capacitor very close to the amp. If that still isn't enough, I would say you're looking at a bigger alternator and another battery.

 

Thanks for the response, tc. By the way, what kind of setup got you 4th in the IASCA finals? I'm going to be rewiring everything once the new amps arrive so I'll make sure I'm grounded properly. I'll just have to check under the hood tomorrow to see if I can easily access the alt.

 

It just takes time. I ran 2 guage for:
Alt - Fuse Box
Fuse Box - Battery
Battery - engine ground
Battery - chassis ground

You might also want to buy some bigger split loom than what is provided by the factory as it gets a big rough stuffing some of that stuff back in. You'll want wire and some new lugs. I went with solder lugs but crimp lugs would work just fine (it was all NASA would allow in the Apollo program) for your wire connections.

If you truck is similar to the Taco, which I believe the 3rd gen is, you're looking at the following post sizes:
Alternator - 1/4"
Fuse Box, Alternator side - 1/4"
Fuse Box, Battery side - 1/4"
Chassis Ground - 1/4"
Engine mounted ground - 3/8"
Solenoid posts - 5/16"
Military battery terminal connections - 3/8"

One other item some people miss is waterproofing. Pick up some appropriately sized, mosture resistant (usually has an adhesive inside) heat-shrink tubing and run enough to cover from 1/4" on the insulation to 1/4" on the lug so there is no exposed wire. Helps keep things in working order.

 

i have the same problem with only 1300 watts, everything dims at idle, the only good fix I have heard of is a 2nd battery

 

I was dimming a little at fill tilt on idle, did the big three and now I have no dimming. I would recommend it. It's cheap and effective.

 

Speaking of small guage wiring, what is the best way to strip off the insulation on anything smaller (or larger, however you look at it) than 8 guage or so? I installed an amp a few weeks back and had a heck of a time stripping the 4 guage power wire. I've never seen a tool that works with wire that large. The same question goes for cutting the wire also.

Thanks.

 

ive also never seen a tool that does that....i just used scissors, worked well.

as for the big 3 upgrade.....where is the best place to get all the wire/connectors? im having difficulty finding big enough wire and connectors....biggest ive found is 8ga.

 

Welding supply store for the wire and connectors (cheap)

Strip the wire w/ a pocket knife

You can get a battery cable crimper (big crimper) at Napa or online (if you make a lot)

I upgraded all mine to 2 gauge

Upgrading the "big 3" is the "big easy". Nothing to it.

 

I had a shop do mine and they ran 1/0 for all the negative terminal grounds and then 8 gauge from the positive terminal to Fuse Box and 4 gauge from the positive terminal to the alternator I believe. He said he checked the ratings on all the positive side connections and said that he used the biggest wire he could have without starting to blow stuff...is this true? If not I will have him go back and upgarde the positive wires too.

He also added 3 additional grounds using 1/0 gauge.



^New engine ground^



^New body ground^



^New frame ground^



^Negative battery terminal with 1/0 gauge^



^Positive battery terminal with 4 gauge and 8 gauge^

Do you think I should have him go back and run bigger cables from the positive out to their respective locations?

Sorry for kind of hijacking, thought I'd post up with my setup.

Fink

 

For those that did it, what kind of wire are you using?
I see one with welding cable so far.

Where did you get it and what was the price per foot?


I am able to get free cable, but I am told not to use it from some and to use it from others.

 

Any car audio place or welding supply...the welding supply is going to be cheaper and I would assume it would have to atleast be the same quality as car audio if not better so either would be fine.

Fink

 

I did and I chose to leave the stock wiring in place and augment it with some 1/0. It took approximately 8' to run from the alt's charging post to the battery, then about 6 feet for the various grounds. Of course I grounded the battery with about 6" of 1/0 to the frame at the stock location, then I grounded the battery to the front engine hook (3vze), then from the front engine hook to the intake plenum, then from the intake plenum to the firewall.

I still need to add some 1/0 from the battery's negative to the frame rails, then run 5 more runs of 1/0 from the b+ to the amps.

 

hehehehe ill edit back with a cutter that I use that also strips 1/0 in under 30 seconds...

EDIT:

http://www.partsexpress.com/pe/showd...number=360-624

Here ya go! She will cut straight through 4/0 copper cable (I personally cut 6 4ga wires at the same time) Anyhow, in order to strip you just cut through the insulation on 2 sides at once, open the jaws, turn the wire 90* and again cut the remaining insulation, then open the jaws ever so slighly so that only the wire can be drawn out - the jaws will keep the insulation from following.

 

From my electrical knowledge, running a bigger wire will never cause stuff to "blow". The wire doesn't determine the load/current, it's whatever is running on the wire.

 

do you experience the same results when "adding" another wire, compared to just removing that stock wire, and replacing it with a larger gauge?

if im not making sense....the wire/cable that goes from the alternator to battery....its 8 gauge i think? maybe 10? well, if i just added 4 gauge, and still had that 8 gauge, would i experience the same results as if i removed the 8 gauge and put the 4 gauge?

 

Probably so yeah...I don't really know.

I'll be going up to my buddy's shop tomorrow to have him run some more wire and talk to him about other terminals.

Fink

 

I've searched and am still trying to understand whether this mod is a "nice to have" or a necessity.

I don't notice dimming but is this the only reason to do the mod? I have a very simple sound system w/ 300 watts and don't plan on adding any more. I don't plan on a winch and off-road lighting is used rarely.

When I did upgrade the sound system, I asked my buddy whether this mod was worthwhile and of course as the shop owner, he said yes. It's a lot of work (according to him) and takes about 2-3 shop hours to complete. I've already asked about pricing and to get a setup like Fink, it's approximately $250 out the door.

What is the true benefit that I'm not understanding? Is it that the alt will last longer being supplied with the right amount or power, or is it that the sound system will sound that much better? I'm just trying to figure out "bang for your buck" on this mod.

Start the flaming...

 

I honestly would not have had this done if I did not need my wires extended, that was my original reason for getting any of this kind of work done...the yellow top I had was the 51R and was tiny and wouldn't start the Runner on extremely cold mornings so I upsized to the D34/78 Yellow and my positive cable was not long enough so I was going to have to lengthen them anyway and my buddy was like, hey, while I'm in there I'll throw in some extra grounds and beef up as much of the wire as I can.

I would not spend $250 on this just to simply upgrade the size of the wires (unless you need to for a massive system but I am running a 2000W amp and I still don't think that warrants upgrading them).

Just my $.02, it is a very nice to have though and the new terminals are great as the negative has posts for aux inputs and the positive has set screw type connections.

My buddy, as far as I know is still sick, I talked to his girlfriend on Thursday and she said he was still sick so I will give him a call tomorrow to check up on him and see whats going on.

Later,

Fink

 

Fink, thanks for this. I already had to get my original cables extended as I couldn't find a 34R anywhere and have been waiting for two months. The 34/78 required longer cables and this was done w/ the bling Monster terminals. The terminals by the way are fully covered by some see-through plastic thingys that came w/ the Monster terminals.

Anyone else have an opinion? If it's not worth it, I figure there's something else calling my money...