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Bronkin' 'Round!
88 351/AOD/4” ProComp 94 351/E4OD/4” Superlift
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Discussion Starter #1 (Edited)
PLEASE READ THIS ENTIRE POST BEFORE ASKING QUESTIONS!!!

Had to start this thread since there is much misinformation and confusion about the 3G alternator upgrade. This is not an install thread, just a guide on where to get the alt you need, a wiring diagram, and pulley sizing. Most photos and some of the text is courtesy of Ryan McCormick of FordFuelInjection.com. Hope he's well, wherever he is.

Why go 3G?
Because your factory alternator is barely adequate for your truck, stock.
Added off-road lights or a big stereo?
You need a bigger alternator!
Need me to show you?

And that's alternator RPM, not engine rpm. The alt spins much faster than the engine.
Alt RPM = Engine RPM x Crank Pulley Diameter ÷ Alt Pulley Diameter.
87-92 is the blue line.
93-96 is the green line.
78-86 is less than the blue line.

There are 3 different mounting styles for the 3G alternator that can be used as an upgrade on other vehicles:

If you have a 66-86, anything with v-belts, or a 87-98 300 (4.9L) or 460 (7.5L): you'll need a Pivot Mount w/ 8.25” ear spacing alternator. Some 90, any 91-92, and some 93-99 non DOHC Ford Taurus will be able to donate it's alternator to your truck. On your v-belt truck, you may also be able to use one that fits the 87-92 serpentine setup (Pivot Mount w/ 7.00” ear spacing) but some may have fitment issues with smog pump location. The Pivot Mount w/ 8.25” ear spacing can be swapped into:
1966-1986 V-belt Mustangs
1966-1987 V-Belt Broncos/E-Series/F-series
1992-1997 4.9L & 7.5L Bronco/F-Series/E-Series
Other V-belt vehicles that can adjust to an 8.25” wide Pivot mount alternator

A wide-eared Taurus alt will ONLY fit a 302 or 351W if it is a V-belt setup since it's wider than a serpentine one.


If you have an 87-92 302 (5.0L) or 351W (5.8L): you have a 2G alternator.


This is an early serpentine style. This can only be replaced with a Pivot Mount w/ 7.00” ear spacing alternator. Minor bracket clearancing will be required.



This can be found in the following cars:
93-99 narrow-eared non-DOHC Taurus
94-95 V8 Mustang
94-00 V6 Mustang
94-97 V6 T-Bird/Cougar
95-98 Windstar
91-94 V6 Lincoln Continental.

The early serpentine car and truck alts on Ryan's site are interchangable but the plug and charge stud are clocked differently to fit the wiring to the bracket better. The Pivot Mount w/ 7.00” ear spacing can be swapped into:
1987-1992 Broncos/E-Series/F-series
1966-1995 Mustangs
Other vehicles that use a 7.00” wide Pivot mount alternator

If you have a 93-96 302 (5.0L) or 351W (5.8L): you have a Side Mount 3G already but a 95 amp one. You DO NOT need to get a wiring harness, as since you already have a 3G, it's plug and play!!! I strongly urge you to get a larger charge cable and megafuse though.
For a 130 amp, you can get that for a:
93-96 V8 Econoline with Rear Air Conditioning or the High Output Alternator options
97-03 V6 Econoline E-Series or F-150
95-01 4.0 V6 Explorer or Ranger

at your local parts house for less than eBay.
You'll need the one for late serp. vehicles.
The Side Mount can be swapped into:
1993-1997 5.0L, 5.8L & 7.5L Bronco/F-Series/E-Series
Other vehicles that use a Side Mount alternator
Or you could try to find one like that at a junkyard.


A Note On Belt Squeal: Some 3G alternators create an extra large load on the belt upon engine startup. There is a later part number soft-start regulator that you can be on the look out for. Read more about this here. Thanks to Fodder, SRWillis, and silver70 for the heads up.

Plug Clocking: Each style may have the rear plugs clocked 3 different ways to fit their various vehicles better. They will still fit no matter the clocking but you can remove the case bolts, and reclock the rear to get your optimum position.

Wiring Harness and Charge Cables: The wiring is very simple. I prefer to grab the harness off of certain donor vehicles and then modifying them if they are in great condition. 94-95 Mustang GT's are my favorite as the charge cable is a great length. Many harnesses are available online if you can't find one that suits your needs.


When you swap to a 130 or higher amp 3G, although you do not NEED a larger charge cable such as a 2 Gauge, it is a great idea. Smaller wires/cables cannot always handle such a load and they tend to heat up, some to the point of melting the wire and could start a fire. ALWAYS make sure you use a megafuse rated at least 15-25 amps above your alternator amperage.

Pulleys: For pulleys, you can either re-use your old one, which sometimes you may need a very small washer to use as a spacer if it rubs in the 3G case at all, or you can get a different sized one. It all depends on your needs. A smaller pulley will spin the alternator faster at idle to create maximum output. A larger pulley will allow the engine to rev higher without driving the alternator to fast. Large 3G alternators are safe to ~15,000RPM max. Again, Alt RPM = Engine RPM x Crank Pulley Diameter ÷ Alt Pulley Diameter.

Factory Carb Users: If you have a Factory Ford carburetor (Holley model 4180) with a wire that connects directly to your 1G alt to your electric choke, get a 12 volt electric choke for a Holley 4160, P/N 45-223, and swap it out. Then wire the new choke to 12 volts with key on.

This post will continually be edited as information pops up. Please post any errors you find so this can be THE thread for 3G interchange information.
 

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Bronkin' 'Round!
88 351/AOD/4” ProComp 94 351/E4OD/4” Superlift
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2,890 Posts
Discussion Starter #2
Bronco Rob said:
Am i reading that right, the 93 Bronco's are a straight swap?
With a larger charge cable and megafuse, they are.
 

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Bronkin' 'Round!
88 351/AOD/4” ProComp 94 351/E4OD/4” Superlift
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2,890 Posts
Discussion Starter #3
DcSkater602 said:
hey a ? for ryan. How do i upgrade the 130 amp 3g to a 200 amp??

thanx in advance

DC
You'll have to take the alternator apart, heat up the solder at 6 points, remove the rectifier from the windings, install the new one and solder that in.
 

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I acquired a 4G alternator for a reasonable sum, with what appears to be the correct mounts for my '96. Other than beefing up the charging cable and so forth, any issues? It's rumored to be 170 amp unit, anyone know?
 

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Bronkin' 'Round!
88 351/AOD/4” ProComp 94 351/E4OD/4” Superlift
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2,890 Posts
Discussion Starter #5
Optika1 illushun said:
i can add info about the EFI 300s if u would like sometime soon.
Either post it up here or PM it to me and I'll add it to the main post.
 

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OUT OF BUSINESS / M.I.A.
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fastpat said:
I acquired a 4G alternator for a reasonable sum, with what appears to be the correct mounts for my '96. Other than beefing up the charging cable and so forth, any issues? It's rumored to be 170 amp unit, anyone know?
The 4G isn't BAD, but it was a failure compaired to the 3G.
The 3G is still Fords #1 alternator. Even though they have made it to a 7G, Ford puts the 3G in vehilces to this very day. When they want the best they ever made.
I've never seen any aftermarket parts for the 4G, so I doubt it can produce 170apms.
 

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Diesel Gynachologist
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11,532 Posts
Bronco Rob said:
Am i reading that right, the 93 Bronco's are a straight swap?

yes even without bigger cables....Ive done it ad so has dogonmutt. we have yet to have a single problem with it. granted the bigger cables are better and I do play to rewire it so I can get the most out of the upgrade but as it sits now it works fine and I noticed a huge differnce over the stock 95amp
 

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Zombie Hunter
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13,681 Posts
Dustin said:
yes even without bigger cables....Ive done it ad so has dogonmutt. we have yet to have a single problem with it. granted the bigger cables are better and I do play to rewire it so I can get the most out of the upgrade but as it sits now it works fine and I noticed a huge differnce over the stock 95amp
Not to sound dumb Dustin, but did this get rid of all the irritating "dimming"? It's not noticeable to anyone else, but mostly in the winter, when i have the cab blower on high, with the lights on, and the radio, and then i do something like turn a blinker on, the dash lights and the radio display dim with the blinker. Not enough to make me think i have any other issues than just too much power in use.
 

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Currently FSB divorced
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956 Posts
Bronco Rob said:
Not to sound dumb Dustin, but did this get rid of all the irritating "dimming"? It's not noticeable to anyone else, but mostly in the winter, when i have the cab blower on high, with the lights on, and the radio, and then i do something like turn a blinker on, the dash lights and the radio display dim with the blinker. Not enough to make me think i have any other issues than just too much power in use.
I'll jump in here- Yes it did. I had a stock alt and got Ryan's 200amp and there's no dimming issues at all with all accesories on!-Bob
 
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Diesel Gynachologist
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Bronco Rob said:
Not to sound dumb Dustin, but did this get rid of all the irritating "dimming"? It's not noticeable to anyone else, but mostly in the winter, when i have the cab blower on high, with the lights on, and the radio, and then i do something like turn a blinker on, the dash lights and the radio display dim with the blinker. Not enough to make me think i have any other issues than just too much power in use.

I had the same problem, It would only do it at night with the headlights on and blower motor. I would come up toa stop and the dash lights would dim alot. the 130amp took care of most of that, I will still get some dimming but hardly any.

the best part is having the power to run the kc lights at an idle without it putting a huge load on teh battery
 

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Bronkin' 'Round!
88 351/AOD/4” ProComp 94 351/E4OD/4” Superlift
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2,890 Posts
Discussion Starter #11
LaNeR88 said:
for a 88 bronc with a 351W i need a late serp alt off ryan's site? and which pulley?
Clarko said:
If you have an 87-92:[/B] you have a 2G alternator. This is an early serpentine style. This can only be replaced with an the following car's alts: narrow-eared non-DOHC Taurus from 96-99, any 94-95 V8 Mustang, 94-00 V6 Mustang , 94-97 V6 T-Bird/Cougar, 95-98 Windstar, & 91-94 V6 Lincoln Continental. The early serpentine car and truck alts on Ryan's site are interchangable but the plug and charge stud are clocked differently to fit the wiring better.
It looks like this:
Since it's a truck, and wont see any more than about 5000 RPMs, I'd get the smallest pulley for the best charge.
 

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Bronkin' 'Round!
88 351/AOD/4” ProComp 94 351/E4OD/4” Superlift
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2,890 Posts
Discussion Starter #12
Late Model Man said:
Will the alts from the 93-96 V8 Econoline, 97-03 V6 Econoline E-Series or F-150, or 95-01 4.0 V6 Explorer or Ranger hook up directly to the alt connector on my bronc?
Clarko said:
Bronco Rob said:
Am i reading that right, the 93 Bronco's are a straight swap?
With a larger charge cable and megafuse, they are.
AKA yes!
 

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Bronkin' 'Round!
88 351/AOD/4” ProComp 94 351/E4OD/4” Superlift
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2,890 Posts
Discussion Starter #14
unixdude said:
Is there an easy way to identify the 160A or 200A 3G? Are the 160A and 200A only available by modifying a 130A 3G?
Yep. You could go get a junkyard 3g, disassemble it, clean it, put one of Ryan's 200 amp rectifier kits in it, new bearings, new brushes/regulator, and bam, new 200 amp alt.
 

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(Is the larger charge cable and mega fuse available in auto parts stores, or is it something I would have to make up?
Can I get the larger charge cable and mega fuse at an auto supply store, or do I have to make it up myself?

Can I purhase the charging cable and mega fuse as a unit from an auto supply store, or do I have to make it up myself?
 

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crank trigger
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8,150 Posts
go to napa and buy bulk cable and copper connectors. get your lengths measured and cut them. strip the ends. then use a torch and fill the connector with solder and stuff your cable ends inside and boom, custom cables. you can get the mega fuse there. i used a 130a circuit breaker. been fine thus far.
 

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Bronkin' 'Round!
88 351/AOD/4” ProComp 94 351/E4OD/4” Superlift
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2,890 Posts
Discussion Starter #18
fartman said:
So if i read right then all 91-95 taurus alt.s will swap into my 81 , right ? Also would I have to upgrade the wire and add the megafuse? Thanks for the thread.
Any non-side-mount alternator will work. You will need to upgrade the cable and add the megafuse.
 

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Bronkin' 'Round!
88 351/AOD/4” ProComp 94 351/E4OD/4” Superlift
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2,890 Posts
Discussion Starter #19
stang96gts said:
Ok, so if I have an 84 bronco with an 86 stang motor (serp belt), what parts do I need to complete the swap?
Same as a serp Bronco. Pivot mount with 7.00 ear spacing.
 

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Bronkin' 'Round!
88 351/AOD/4” ProComp 94 351/E4OD/4” Superlift
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Discussion Starter #20
lightnin said:
Nother stupid question. The 7" and the 8.25" 3g have the same case just the mounts are closer to the case on the 7"? I am picking up one from a 94 V6 Mustang and it has the 2 big holes. Just wanted to make sure it is 130-5A alternator.
Right the closer holes are the 7" one which works for serpentine or v-belts.
 
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