doc76239

So I am trying to find more info on the big 3 wire upgrade. I tried doing a search but was unable to locate anything relavant. If any one has a link to this info would be great.

ovrrdrive

It involves using a 3" solid core copper positive battery cable. They're very hard to find these days and cost about $800/foot to purchase.

Good luck.



Just kidding...

Big 3 refers to upgrading the wire gauge sizes of the main 3 wires in the electrical system.

1) Battery negative to chassis
2) Alternator to battery positive
3) Chassis to engine

Btw, I'm really surprised that the search you did came up with nothing on this...

Maybe try google after you search yotatech.

ovrrdrive

A quick google search turned this thread up:

link

doc76239

Thanks for the link, but i was looking for some thing more 2nd gen 4runner.

TNRabbit

Same concept. Heavey gauge wiring between battery negative and chassis, alternator and battery positive terminal, and ground between engine & chassis.

mt_goat

Ok lets look at these for the early 90s trucks. With all of these you can either replace the existing wire with bigger wire or (my favorite) leave the existing wire in place and run another wire parallel to it.

#1 is easy, just a little short wire in plain view that screws to the body on the inner fender. Take the time to clean the body sheet metal with some sand paper.

#2 is the hardest on our trucks because the battery & fuse box is on the other side of the engine bay from the alternator and the wire goes from the alt to the fuse box then to the battery. I took the fuse box apart so I could connect the parallel wire directly to the same connection points as the stock wire. Make sure you route this (+) wire where it won't get cut or damaged and protect it well with split loom. Remember (+) wires that get cut and grounded on something can start big fires!

To the alt:





I almost forgot if you upgrade the battery to the fuse box wire you must keep the fuseable link that is right off the battery (it is the smaller section of wire about 4-6 inches long). If you add a second wire parallel it also must have a fuseable link (This was one place I upgraded the existing wire rather than adding a parallel wire. (not sure how safe it is to add another fuseable link).

This is what my fuse box looks like after the upgrade, I used 4 gauge from the fusebox to fuseable link and the fuseable link is connected directly to the battery:



#3 Bolts to the block (probably very dirty so clean up the contact surface) and runs to the battery (-). I've found this one is actually a pretty big cable already and redundancy is always a good thing with grounding, so I ran an extra block ground to the alt/block mounting bolt.

AH64ID

Would there be anything wrong with running a wire (2ga) from the alt to the battery with a say 125amp fuseable like (100 amp alternator), and just leaving the stock setup? I am not worried about anything drawing more than the OEM wiring can handle, except what is atteched to the battery directly.

Bumpin' Yota

AH62ID - nope, no issues atall. My 1/0 run from the alt to battery is unfused actually...

What helps everything a lot is grounding redundancy. I have 2 grounds to the chassis, one at the OEM location and one behind the charcoal canister on the fire wall. I have 2 grounds to the engine, one to the block and one to the head. The last set of groud that I havent done are going to be from the frame rails to the block and to the battery.

And while im in there im replacing the OEM wire that feeds the fuse box with a nice fat 1/0 if itll fit...

AH64ID

My dad is a boat mechanic so I know well all about proper grounding, and how DC is differnt than AC in that it needs to return to the start point, hence a good ground.

With the engine out I plan to beef up the chasis ground, and then block ground. I alreay have a huge frame ground. When I wired my winch I ran cut the ground in half and bolted it together with one of the bolts holding my ARB on, so I think its grounded well enough..

As far as the alt wire, I figured that was safe.. but none the less I will probally acquire a 125 fusable link just to be safe. It should really help when winching.

I had my OEM alternator rebuilt with a toyota 100 amp winding, then put a smaller pulley on it so it puts out max amps at about 1500rpm. The only issue I have is it still goes offline at about 700rpm. I havent figured it out yet since the guy who built it said it should be putting out about 35-40 amps at that speed, must be part of the OEM voltage regulator.. .I wonder if there is any way to fix that....

mt_goat

See post #19 here: http://www.tacomaterritory.com/forum...ght=Alternator

mt_goat

The fuse sounds like a good idea to me, if you do connect the alt straight to the battery. In a perfect world you wouldn't need any fuses, but stuff happens.

AH64ID

Cool thanks, I'll get a hold of them, and the guy that did mine to see what was and wasnt done.

The guy who did it does all the the rebuilds on alternators and starters for my dads boat business. He does good work, just doesnt work on too many toyotas

mt_goat

I found the 4 gauge to be a pretty tight fit in the fuse box openning. Bigger and you may have some extra work. IIRC the stock was about 8 gauge so going to 4 gauge is a pretty big upgrade (looks to be about double the OEM wire to me)

Bumpin' Yota

this is true and you are correct I should have fused my alt to battery line.

doc76239

Cool this helps alot thanks guys.

AH64ID

I was looking at that tread again.. My alt put out aperage at low rpm's on the bench, just not in the truck. Is there something in the truck that would prohibit that?

Bumpin' Yota

wow the peeps on that site LOVE the 3.0 I see. Too bad they dont realize the 5vzfe has just as big a HG recall as the 3vze...lol

The alternator generates current as the electrical system needs it. Voltage is the best indicator of whats going on in your electrical system. You probably never saw that much current in the truck at idle but your voltage was probably at least 13.0v or so....which means it's workin fine!

AH64ID

I know its offline, or so it seems, as my lights dim and my ARB compresser slows down.. but as soon as I hit 755 rpms its putting out serious energy, but at 750 or lower... nada

Bumpin' Yota

ah thats normal, my 190 amp unit used to not turn on until about 1100rpm...

In your case though you can just bump the idle up to 800 and not worry about it!

AH64ID

What I thought was odd was I put a much smaller pulley on it and nothing changed.... so what causes that? Why will it put power at idle rpm on the bench, but not in the rig?