Ford Large Case G3 alternator setup for fans

[Craig]

This will be documenting the installation of a Ford large case G3 alternator. I pulled mine from a 1993 Ford Taurus with the 3.8 engine. $16.99 plus $5 core, $22 bucks out the door. This is a "3 wire Alternator" i.e. has a sense wire. If your not up for an adventure, Jeff has the Mean Green alt.that will bolt right in

All of these Ford vehicles had the 130amp 3G

(1994-95) Ford Mustang 5.0L
(1994-00) Ford Mustang 3.8L
(1994-97) Ford Thunderbird, Mercury Cougar 3.8L
(1990-95) Ford Taurus, Mercury Sable 3.8L
(1993-99) Ford Taurus, Mercury Sable 3.0L
(1995-98) Ford Windstar 3.8L & 3.0L
(1991-94) Lincoln Continental 3.8L
(1992-97) Ford F Series Pickup
(1992-96) Ford E Series Van

There are two styles that will work, it just the mounting holes are farther apart. The one with the mounting holes father apart are a dime a dozen at Pick and Pull the others will take a little searching as they fit into a lot of other projects with serpentine belts.


You will need to swap the pully with your stock alt. Impact gun is a must here







While I was there I also pulled the alt. wiring harness. I followed the 3 leads as far and I could and cut it off ( running out of time as they were closing) but the main power lead is 4 ga
I got is home and swapped the pulley that was painless for a change. The mocked up the alt. side by side. The G3 has a larger swing mounting bolt. The 76'ish mounting IH bracket I have has a spacer that goes between the alt. and the bracket, it about 3/4" long. But even with it out the new G3 is about a 1/4" bigger then the bracket. Options ( cut the alternator to fit, or modify the bracket) I decide to modify the bracket, this way with a larger spacer I could mount the old alt. and the G3 interchangeable. I used my trusty 4.5" dewalt plasma cutter and removed one side of the hanger mount. Need to clean it up and weld to fit the G3 and make a spacer so I can re install the stock alt. Wife need's the Scout off the driveway for a party Wednesday.

My plan is to leave the stock aternator wiring ty-rap out of the way and just install the G3. I plan to bypass the dash amp meter gauge and make the two alternators interchangeable for emergency trail fix. All seems easy enough, but my camera is broken Waiting on a new one, hopfully this week so I document this for those who just like to look at pictures .

[Craig]

Made a little progress. Got the tab re welded and the G3 fits great. Found out the G3 has a 7/16 hanger bolt vs the stock one which in 3/8. Drilled it out, problem solved. I mount the stock unit back in while I get a few parts, just drill out the alternator to fit the 7/16 bolt

The unit I have mounted up fine, but if I can find the other model I will pick one up, as it will move the alternator up 5/8" I post up the difference once I get one.

[Craig]

I was going in circles for a moment. Ford starters don't have a solenoid like GM does and I keep seeing where they would connect the output of the G3 alternator to the battery side of the solenoid.
That got me thinking about how the Scout is wired. Then I found this in the FAQ on the Binder for Remote starter setup.

more info on the MADelectrical site too.

[Craig]

I took the MAD picture delete the Horn relay added a bit of text for reference.

Reading his website, he really does not what a big cable going to the battery as it's hard on a battery and alternator when you charge it up to fast, that's the reason for the 10 ga 7-10 in length to get a small voltage drop and control the charge rate.
Notice how the sensing wire is remote from the alternator, not like the photo above ( yellow wire) where they sell you a pig tail harness and just connected it back to the alternator.

edit.. changed the pic and now using a larger charge wire, and the amp meter is bypassed all wire on the negative terminal

[Craig]

OK I picked up the other style and found out the bracket needs a touch with the grinder to allow the case to swivel back and forth. Also got a terminal block off a chevy to use for distribution. Just need a ford solenoid and I good, was in a rush at the yard and did not have time to get one.
I like the new style as it move the alt up a bit away from the exhaust and away from the inner fender too.

[SSMinnow]

Will a york compressor fit on top of that bracket for air?

Just FYI attached it how I am doing mine, using mad as reference. I have ran into a couple of other snags, that need fixed first.

[Craig]

Originally Posted by SSMinnow

Will a york compressor fit on top of that bracket for air?

Just FYI attached it how I am doing mine, using mad as reference. I have ran into a couple of other snags, that need fixed first.

Yes that is a stock bracket, which will hold a york a/c unit.
I have a cast iron bracket too, but this one is off a 76's IH I believe.

Are you running a 1 wire alt? or just don't have that wire draw in?
I like the mad drawing, but will change it to look like a Scout setup. I will also by pass the amp meter..
I was looking for a Delco CS144 alt but everytime I looked at PNP they were gone, but every Ford had a G3 which is rated at 130amp, Just yesterday while getting a couple wires and walking through the cars I found a CS144, Thinking I might grab it for my Pickup.

[SSMinnow]

No its a three wire, as I wire it I make notes. I have a rough draft that is ever changing.

[Craig]

I know what you mean, by the ever changing. Last night I mounted the Ford solenoid on the fire wall and connected up the wires from the alternator. Found out IH uses a "special" wire for the ignition side, it's a single wire brn/wht that is resistive. This way you don't need to have a resister in line with the wiring.
Still debating on the charge wire size, MAD uses one size smaller that the alternator output wire. The Fords have a 6 awg output wire, I used an 8 awg for my charge wire.

Still need to get a battery cable from the solenoid to the starter and install jumper on the starter. By-pass the amp meter. I might leave the bulkhead connecter alone as it not the main charging circuit anymore.

[Craig]

Got a couple battery cables, the S10 have a nice 3' 4ga starter wire. Got one for the selenoid to starter and one from the alternater to the block battery ground connection, trying to make sure I have good grounds to the block, frame and body.

While I was out there pick up one of these for a weldunater

[Craig]

The more I looked the more I figured out most everyone else has a cast iron mounting bracket. The only option then is to get a GM CS144 AC Delco alternator. It fits in the bracket nice, I will bolt it up to see if the stock belts will work with it. I pick one up on 25% off Wednesdays at pick and pull.

I did noticed that the dully V belt pulley center section is thicker, than the stock pulley, so you can't use the lock washer as there is not enough shaft sticking out. I would also use some green locktite on the pulley shaft too to make sure it does not spin. Also the adjustment bolt is metric, I just used a smaller 5/16 bolt for now. ( so don't toss the stock one at the JY)

Edit... In my hurry yesterday to pull this puppy I never looked at the wiring real close until just now, this one is easy to setup as it only has 1 wire Going back to PNP I found both types of connectors. Some with 3 wires and 1 wire. Not to be confused with one wire alternators.


Ya I know more midnight photography so the pic's are crappy.

[Craig]

Finshed up the wiring upgrades and everything is working great. Moved all my misc. wires off the battery and onto the new terminal block.

[Craig]

Following up on the CS144, I found you need to make an 1 1/8 spacer to align up the pivit arm. I just used a piece of 3/4" pipe with some 3/8" washer weld to each end. I update the picture with some more info too. For a quick install you could buy/build the pigtail adapter with the resister and plug in the stock alt. harness and run a large 6 ga wire from the atl. BAT post to starter post. The stock wire that was connected to the old alt. BAT post should be tape up and not used or moved to the starter post as it would fry the amp meter if you used it. This would keep most of the wiring stock, but you would not have an id10t light which could be handy. I would still move all the connections to the negitive side of the amp meter to be safe too.

Edit... If your out at PNP look in the Ford mini vans, they have a 4 ga wire with fusible links that could also be used as a BAT wire. Plus you need to ground the case of the new alternator back to the battery. Run a large wire off the back of the case (metric bolt) to the location where your neg battery cable is attached to the engine...

[Craig]

You can buy a pig tail or make one, as Kragen sell one half for $4 and you just use the one off the JY alt. I would recommend getting a plug that has the S wire so you have a sense wire, this tells the alt to make more when your using more.

[Plug Ugly]

reading you r list of vehicles, you need to be careful as the trucks and some of the later vans had a different style case case. it was a 3 bolt case that had entirely different mounting.