Alternator Help

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Alternator Help

fords4life
This post was updated on .
I'm not sure what I have.  I believe this was a 3g conversion, but all the conversions I've seen used the plug on the outside of the alternator.  This was hardwired and had to be cut to remove before I pulled the motor.  Any thoughts?  I want to clean it up with plugs so I can remove early if needed.  Nothing was plugged into the black box and no external voltage regulator.

EDIT: The pigtail may be a plug after doing a little more research, but I couldn't get it off to save my life.

Thanks!

1986 F-150 SC 2wd 4spd 302EFI Base Model all OEM motor/trans/emissions equipment.
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Re: Alternator Help

Gary Lewis
Administrator
You have a 2G alternator, as shown in the pic below from this page: Documentation/Electrical/3G Conversion.  Hopefully that page will explain how to do the conversion because the 2G is also called the "fire starter".  It was a known problem that Ford phased out pretty quickly in favor of the 3G.


Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

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Re: Alternator Help

fords4life
Thanks Gary.  Not sure why I couldn't figure it out.  Probably has something to do with 2 Long days and only a few hours of sleep in between.
1986 F-150 SC 2wd 4spd 302EFI Base Model all OEM motor/trans/emissions equipment.
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Re: Alternator Help

Gary Lewis
Administrator
No prob.

There is a TSB on the 2G issue.  The issue had to do with poor connections, and since you have a hard time getting that connector out you might want to make sure it is good.
Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

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Re: Alternator Help

fords4life
I'm not gonna chance it.  Too much $$ and sweat equity into the truck to risk something like that.  I'll but a 3g alternator and do the swap.
1986 F-150 SC 2wd 4spd 302EFI Base Model all OEM motor/trans/emissions equipment.
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Re: Alternator Help

Gary Lewis
Administrator
That's an even better plan.  
Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

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Re: Alternator Help

fords4life
Gary - Just a note.  You mention in the 3g page that trucks with v-belts use an 8.25" mount spacing with a more that it needs to be confirmed.  The alternator that came off my 86 has a 7" mount spacing and I'm running v-belts.
1986 F-150 SC 2wd 4spd 302EFI Base Model all OEM motor/trans/emissions equipment.
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Re: Alternator Help

85lebaront2
Administrator
In reply to this post by Gary Lewis
A lot of the service 2G units (the ones Matt carried) came with a permanently installed connector and a nice pair of splices. Part of the 2G issues are not completely the alternator's fault, the voltage sense is moved beyond the alternator's fusible links, so if the links blow the alternator goes full field and burns itself up.
Bill AKA "LOBO" Profile

"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413

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Re: Alternator Help

ArdWrknTrk
Administrator
In reply to this post by fords4life
The 130A 3G that we all look for has a bigger body and with 7" C-C it won't swing far enough to adjust.
That's why we say get the 8.25" model.

I agree with Bill.
A lot of replacement 2G alternators came hard wired (eliminating the fire prone plug, and forcing you to cut away the wire ends that were compromised)

Because it took even Gary forever to understand the differences, I'm going to restate it;

There are two amperages commonly available, 95 & 130A.
95A models have FOUR holes in the ribs and are 135mm in diameter.
130A models have TWO holes in the ribs and are 148mm in diameter.

The ones we are looking for swing mount, opposed to side mount or V-mount or anything else.
They will have two mounting 'ears' with holes 180* apart.
One pivot side ear that the long shank bolt fits through and one threaded (in most cases) adjuster ear.

The mounting holes also come in two 'flavors', 7" C-C and 8.25" C-C.
If you have swing mount you want 8.25".
If you have a fuel injected engine with a polygroove belt (except for 300 I-6) you want the 7" model.

ETA: should I start a list of donor vehicles and Lester numbers, or has Gary finally posted that info?
 Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.
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Re: Alternator Help

Gary Lewis
Administrator
Jim - Thanks.  I missed this.

And it has taken me a long time to get my head around it.  Operative word is "has" as I'm not sure it is in the past tense.

In any event, we do have two Lester #'s posted here: Documentation/Electrical/3G Conversion and on the Choosing An Alternator tab.  But if you have more please post them here and I'll get them included.  (And if you already have and I've missed that then I'm sorry.)
Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

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Re: Alternator Help

ArdWrknTrk
Administrator
Ok, I believe those numbers are for the 8.25" 130A with a tapped hole, and without a tapped hole.
Or maybe they come with different clocking...

If I can get some time to go digging I will try to get the 7" numbers and the numbers for both sizes of 95A alternators.
This takes time on my phone because of the lack of tabs and the need for me to zoom in order to read the charts.

The DB Electrical site then lists the Lester numbers once you have the proper application. (at least that's how I do it)

It's a shame Bills son Matt doesn't distribute parts any more.
I'd imagine he had all that information at his fingertips.
 Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.
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Re: Alternator Help

fords4life
In reply to this post by ArdWrknTrk
ArdWrknTrk wrote
The mounting holes also come in two 'flavors', 7" C-C and 8.25" C-C.
If you have swing mount you want 8.25".
If you have a fuel injected engine with a polygroove belt (except for 300 I-6) you want the 7" model.
This is where my confusion is.  I have a 1986 EFI 302 with v-belts.  Since the truck is at my Dad's house, I had him measure and he said the mounting holes are 7" C-C which doesn't match up with what you stated above.  I can't find a drawing of a 7716 alternator to confirm what the spacing should be, but the sticker down below would indicate a 7716-10 alternator, which from what I can find is supposed to be a poly groove belt application.  Assuming I have a red headed step child.

1986 F-150 SC 2wd 4spd 302EFI Base Model all OEM motor/trans/emissions equipment.
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Re: Alternator Help

ArdWrknTrk
Administrator
Does your alternator swing, and use a quadrant for an adjuster, or is it mounted to an aluminum casting, and sit pretty much on top of the engine?
 Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.
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Re: Alternator Help

fords4life
Mounted on the bottom left and it swings.  I didn't get a good photo straight on, but below shows the mounting ear for the side that swings.

1986 F-150 SC 2wd 4spd 302EFI Base Model all OEM motor/trans/emissions equipment.
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Re: Alternator Help

ArdWrknTrk
Administrator
So, if you want the 130A you should get the 8.25"
If you want the 95A I think you could use the 7"C-C.
 Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.
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Re: Alternator Help

fords4life
Jim - If the plug was the issue and the plug is gone, is there really a need to replace if it’s working properly?

Looks like there are 7” 130a versions if I’m looking correctly.  Any advantage to the larger frame for the same amperage?
1986 F-150 SC 2wd 4spd 302EFI Base Model all OEM motor/trans/emissions equipment.
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Re: Alternator Help

ArdWrknTrk
Administrator
fords4life wrote
Jim - If the plug was the issue and the plug is gone, is there really a need to replace if it’s working properly?

Looks like there are 7” 130a versions if I’m looking correctly.  Any advantage to the larger frame for the same amperage?
Hopefully not.

Alternator rebuilders resorted to hardwiring them because too many people did not follow the TSB and replace the plug every time any component of the charging system was serviced.
Then they would try to say the alternator was no good, even though it was the fault of the trucks harness.

First, there are several issues with the 2G.
Plug contacts get wet and corrode, leading to heat, which leads to more resistance and corrosion, which makes for more heat, which leads to.......

Second, that heat causes the plug to melt, whereupon the alternator output goes directly to ground of the case.
Which causes the regulator to step up the output, and (if you're lucky) the diode board (rectifier) to have a meltdown.

Third, as Gary pointed out, the sense wire is on the other side of the fusible link.
So, if for some reason the fusible link goes open, the alternator goes full field with nowhere for that charge to go.

Fourth, the decision to use a plug dictated the use of TWO 10Ga. wires, because you can't really plug in a 60A 4 or 6Ga. cable and have a secure enough connection to pass that juice.
These Bk/Or wires then splice together into a fusible link, and that goes to the trucks main harness.

It's a patch on a patch on a patch in order to meet a mandate from Dearborn to make the alternator connections quicker and more foolproof.


There are 7" 130A 3G's.
I sent one to Gary for Big Blue.

But if you have the 7"C-C mount and the 148 mm diameter 130A case you won't be able to swing it very far to adjust it (if you can get the pivot bolt in in the first place)
 Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.
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Re: Alternator Help

Danny G
In reply to this post by Gary Lewis
This may help with the list:

https://alternatorparts.com/ford-type-3g-4g-6g-series-high-output-alternators.html

1986 F-150|Standard Cab|4x2|300Six|C6Transmission w/3.08 rear|Name:TBD
2021 Ranger XLT Super Crew
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Re: Alternator Help

fords4life
That is a holy grail right there. That's what I've been trying to find with no luck.  Thank you!
1986 F-150 SC 2wd 4spd 302EFI Base Model all OEM motor/trans/emissions equipment.
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Re: Alternator Help

Gary Lewis
Administrator
Yes, that's a good find.  I've added that info to the bottom of the Choosing An Alternator tab here: Documentation/Electrical/3G Swap.  I think we (I?) need to clean that tab up, but wanted to see what y'all thought about it first.

As you'll see, it appears to me that there are only three alternators in that list that are appropriate for our swaps.  So I only added those to our page.

Thoughts?
Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

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