RustBucket

iTrader: (1)

I'm looking into the GM alternator swap for the 4Runner, hoping to replace the stock 60A with a standard 100A GM one. I'm looking for input from others that have done this swap successfully and can guide me in the right direction.

Here's a succinct writeup that's helped so far: http://www.toyotaoffroad.com/Article.../chevy_alt.htm

It looks like I can do this project with 4 things:

1) TG GM alt bracket: http://www.trail-gear.com/alternator-components

2) A GM alternator, probably a CS130 or CS130D from a 94-97 Chevy S10

3) Some heavy gauge wire for the charging post of the alternator

4) A plug adapter: http://store.alternatorparts.com/partno461804.aspx


A few questions

- Is the plug adapter the right way to go? I'd prefer not to hack my wiring harness if possible.
- I'll look for an alternator at the junkyard. But if I can't find a good one I'll buy a new/reman one. What are your preferred brands? Is Remy OK?

RustBucket

iTrader: (1)

Oh, I guess I also need to swap my V-belt pulley from my original alternator onto the GM alternator since it has a serpentine belt groove style.

RustBucket

iTrader: (1)

A question for the electrical gurus:

I want to use a 12SI GM alternator. Typical writeups involve connecting wire #1 on the GM terminal to the L wire from the OEM Toyota harness. This is the charge light wire.

Many writeups reference attaching a parallel path with ~50ohm resistor across the charge light. This way when the truck is cranking the alternator will still excite even if the charge light is burned out.

However, referring to this document: http://www.autoshop101.com/forms/h8.pdf

We learn that the IG wire is actually designed to provide the initial excitation to the alternator.

Can I simply connect the IG and L wires at the alternator connector? This will allow the IG wire to excite the alternator. That circuit is broken when the key is taken off START if I understand it correctly, so the light can still function normally.

osv

this is for a 22re?

I installed the 12si-based powermaster alternator(PM47294), it came with the v-belt pulley, and it didn't require that plug adapter from alternatorparts... if you need that adapter, pm me, I have the one that I didn't use... I think that the 12si-series is smaller?

the alt warning light comes on when the ignition key turns on, I didn't have to install the resistor, and I used that tg gm bracket, but with a metric bolt, the bolt it came with was a really sloppy fit... got the alternator on sale at advance auto, with a coupon, it's 140/80amps, but you would pay a lot less at a junkyard, for less amperage... it came with a long wire back to the battery post, which should have a fuseable link in it... if I recall correctly, I left all of the Toyota wiring and fuses unaltered, except for the connections at the alternator itself... there are multiple wiring diagrams on the 'net for that, just make sure that you don't get it mixed up with the one-wire hookups.

RustBucket

iTrader: (1)

Hey osv, thanks for the reply. Glad to hear you had a successful install, how long have you been running it?

I am getting a 12si rather than a C130 unit. I think 94 amps will be fine, just looking for a modest bump over 60. I got a pigtail that plugs into it so I won't need the connector I listed on the first post.

Yes, I am planning to run a heavy wire from the new alternator post to the battery with a 100A fuse in line.

So my two outstanding questions are these:

1) Is it necessary to make a secondary energizing path parallel to the light? osv, you didn't install one and everything seems to be good for you. This question is why I was asking about doing something with the IG wire on the alternator harness.

2) Some people have talked about doing something with the OEM wire that came off of the original alternator post. That wire runs to an 80A fuse next to the battery. I have seen people putting a jumper from that fuse to the positive battery terminal for some reason. It sounds like you left all of that junk alone and everything is still working fine for you.

RustBucket

iTrader: (1)

Sorry, yes this is a 22re.

osv

I believe that I jumped a wire for that energizing path you are referring to, at the back of the alternator, where it hooks up to that pigtail... but I don't want to be specific, because I can't remember the exact wiring offhand... probably hooked one of the pigtail wires up to the alternator output(?), since it's hooked up to the battery post... I have two connectors screwed down to the alternator output post, but everything is wrapped up in shrink wrap and tape.

I saw where people have replaced that Toyota factory wire to the 80amp fuse, but it's not a logical thing to do, because they didn't upgrade the fuse rating... the wire that is there is already rated to carry more current than the 80amp fuse that it's hooked to, so why put a bigger wire in there? the fuse should always blow before the wire melts.

I think that the key here is to not increase the current draw through that 80amp fuse path... for instance, if you need to hook up a winch, it'll probably get done on it's own fused connection to the battery.

RustBucket

iTrader: (1)

So in reference to the large wire that came off of the OEM alternator post -- did you just leave it unplugged and sitting there?

RustBucket

iTrader: (1)

I am studying the factory wiring diagram. That wire comes from the battery, through the 80A fuse, and splits to go to the alternator and to other stuff like the heater blower and the AC. I don't think that connecting the other side back to the battery will make any difference. The other accessories already have a path to power. This is the B circuit on the diagram.

v_man

rustbucket , just curious as to why you are upgrading alternators ? You running a bunch of extra circuits on your rig ?

RustBucket

iTrader: (1)

Extra light, efan, winch. I'd rather not have the stock alt struggle at full load all the the time. Then I also have the headroom to add more things if needed later.

osv

I think that I remember that point being made when we had that thread about the power steering fluid catching fire on the alternator :-0 gotta go back and look at the wiring diagram, but one question might be, how big is the fuse in the b circuit?

i probably left as much of the oem wire as i could, this is probably the diagram i wired it to: https://web.archive.org/web/20120905...%20Project.pdf

Killgore Trout

i just did the GM alt on my truck, i used a 10si 120 amp alt, ...comes with the correct pulley for a 22r,.......i ran the sense(red) wire from the alt (gm alt pigtail, 6$ at any auto parts store) to near my batt pos where my main distribution point is,....i hooked the lamp(white) wire on the gm pig tail to the charge light wire only (use a jumper wire on the plug, just stick in in the slot for each wire and ground the other end until the charge light comes on),....i also ran the 50 ohm resistor inline on this wire,....they are a couple bucks at radio shack, easy to install and everything works perfectly i also ran a 4awg wire from the alt post to my battery pos with a 120 amp circuit breaker inline.
i only tapped into the lamp wire on my original wiring, everything else is still hooked to the unplugged-plug and taped up.
all my electrical works, charge light works, lights are bright and battery stays charged.

Killgore Trout

http://www.ebay.com/itm/GM-CHROME-120-AMP-1-ONE-3-THREE-WIRE-SBC-BBC-CHEVY-ALTERNATOR-ES-1001-C-/350970868932?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item51b77e74c4
i first used this sellers website (Skip White Performance) when i put HEI on a 71 sbc, they have great customer service and i have never had a problem with their stuff. They have a regular site and always have a ton of ebay auctions, this is the alt im running right now....like there werent enough options already lol.

RustBucket

iTrader: (1)

So Killgore, you left the original alternator post wire alone?

Also can you give more details about how you wired in the resistor?

Killgore Trout

-original charge wire, (thicker white wire with ring terminal) i simply folded over and taped up
-the resistor is an elongated rectangular cube shape, similar in size to the little tube mechanical pencil lead comes in,...from each end protrudes a thick solid wire, about 1 1/2 long. i cut the white wire on the gm pig tail,...striped about 2 inches back on both cut ends,...twisted the resistor in, in line with tight neat wraps, put a couple small dabs of solder on for peace of mind and heat shrink tubed over the whole shebang. then hid the lump in some corrugated plastic loom covering.

RustBucket

iTrader: (1)

What do you hope to accomplish with the resistor? The way you've described it, it is in parallel with a small amount of wire, but still in series with the charge light.

Killgore Trout

Rust, i installed mine based on a write up i found while prepping for the swap, im at work now, so i grabbed an old electrician and hobby car restorer and asked him the details, ....my set up is not correct, the resistor needs to bridge the charge light circuit, paralleling the bulb its self. The lamp wire on the alt plug is the ground wire, i havent dove in to find the charge light power supply under the hood yet. Thanks for inspiring me to get a better grasp on this idea. Since the sense wire is separate, it is still fuzzy as to how exactly the bulbs presence effects excitation if it effects it at all.

RustBucket

iTrader: (1)

Right. When I look at the wiring diagram of the charge light it looks like there's another path for 12V to get to the alternator even if the bulb burned out.

I'll be interested to hear what you find out!

Killgore Trout

Ok, so with the original set up, maybe the excitation involved the lamp, once the external regulator is removed and a sense wire is placed either at the battery terminal or somewhere down stream at a point of 12v draw, the charge light wire is there to simply provide a ground in event of a charging problem, the internal regulator manages that. I cant see at all how a burned out bulb will cause the gm alt to stop charging.