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3G alternator new or used?

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86-350-460-dually

3G alternator new or used?

I still have to test it, but I believe my alternator has taken a dump. I read the 3G conversion page on here a few times. It looks possible, just need to find the alternator and grab the electrical cord with it.

However, the one thing that concerns me a bit is, how do I know this alternator works, and will continue to work for a short period of time? I mean, I'd love to have 90 or 130 amps out of my alternator.

Do you disassemble these alternators after you find them?

Adam

1986 F-350, Dually 4WD, C/C with the 460/7.5L

Gary Lewis

Re: 3G alternator new or used?

Administrator

A salvage will usually give you an exchange if you bring it back w/in a certain period of time. And most part stores will test an alternator for free.

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

FuzzFace2

Re: 3G alternator new or used?

I have found new parts cheap on Amazon and I may go that way when the time comes.

The only thing you may need to take apart would be the pulleys to swap and space out with a washer.
Dave ----

Dave G.
81 F100 flare side 300 six / AA OD / NP435 / 2.75 gear
http://cars.grantskingdom1.com/index.php/1980-Ford-F100?page=1
81 F100 style side 300 six/SROD parts truck -RIP
http://cars.grantskingdom1.com/index.php/1981-Ford-F100

ArdWrknTrk

Re: 3G alternator new or used?

Administrator

In reply to this post by 86-350-460-dually

It may just be the 2G "firewire" charge pigtail that has failed.
There are cheap ~$7 kits to replace that.
If you have a parts store test any alternator, make SURE they test the diodes and not just the output current.

This is the one I'm using.
It's been good for some years now.

$67 new, delivered to your door, with a one year warranty.

I had bought a fused charge cable and the regulator harness from a company (RJM) now out of business, but I see them available on eBay and even from DB itself.

You could make your own if you're handy.
You're going to need *about* 30" lead to reach a fuse mounting point on the inner fender and another foot long cable to go from fuse to where the battery+ nuts to the starter relay.

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.

Steve83

Re: 3G alternator new or used?

Banned User

In reply to this post by 86-350-460-dually

86-350-460-dually wrote

I still have to test it, but I believe my alternator has taken a dump.

This caption explains how to test a 1G:

The PREVious caption explains how to test a 2G & 3G (same VR).

86-350-460-dually wrote

...how do I know this alternator works...?

My thinking has always been: very few vehicles go to the JY for a bad alt. And very few vehicles with bad alts are driven around until they're wrecked. And very few alts GO bad just sitting in the JY, or are damaged (latently) in a wreck. So the vast majority of JY alts are probably still good, which is what I've observed from the MANY JY alts I've bought (I've lost count, but certainly more than 20, and I think I've only gotten 1 DOA, which the JY happily swapped out). But I also frequently find shiny-clean alts in the JY with new reman stickers on them, and they cost the same as the filthy alts.

86-350-460-dually wrote

...and will continue to work for a short period of time?

Even new, that's NOT a certainty. But for the money, I haven't found new to be worth it - all my alts are JY, and I have very few problems.

86-350-460-dually wrote

Do you disassemble these alternators after you find them?

Not usually. But now that I have my sandblaster back at 100%

, I probably will.

But for most people, it's usually sufficient to simply CLEAN all the mounting surfaces, and the output stud & terminal so there's good metal-to-metal contact everywhere.

86-350-460-dually

Re: 3G alternator new or used?

In reply to this post by ArdWrknTrk

This is the one I'm using.
It's been good for some years now.

$67 new, delivered to your door, with a one year warranty.

I don't know how to put that stuff in quotes^

I'm curious if that one fits the V belt or the Pully system? I have the V belt system.

Adam

1986 F-350, Dually 4WD, C/C with the 460/7.5L

86-350-460-dually

Re: 3G alternator new or used?

In reply to this post by Steve83

Thanks for all that info Steve. I'm planning a trip this week to my local JY, but we're a small town and only have one. With that being said, I'd just like a ballpark estimate of the price/alternator that you would expect to pay? This is my first time to the JY hard, so I don't know what if their pricing will be fair.

Adam

1986 F-350, Dually 4WD, C/C with the 460/7.5L

ArdWrknTrk

Re: 3G alternator new or used?

Administrator

In reply to this post by 86-350-460-dually

86-350-460-dually wrote

I don't know how to put that stuff in quotes^

I'm curious if that one fits the V belt or the Pully system? I have the V belt system.

When you hit reply the pop up window has a a ["] button at the top left, or you can manually enter the html tags to bracket the text you wish to quote.

The alternator I linked is for a 3.8l Taurus. It comes with a serpentine pulley installed. You would need to swap your current V-belt pulley, as explained in Gary's upgrade tutorial.
This is much easier if you have an impact gun.

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.

Gary Lewis

Re: 3G alternator new or used?

Administrator

ArdWrknTrk wrote

When you hit reply the pop up window has a a ["] button at the top left, or you can manually enter the html tags to bracket the text you wish to quote.

The alternator I linked is for a 3.8l Taurus. It comes with a serpentine pulley installed. You would need to swap your current V-belt pulley, as explained in Gary's upgrade tutorial.
This is much easier if you have an impact gun.

The only issue I have with quotes is that if the previous person has also quoted you get both quotes. But, it is pretty easy to take out what you don't want.

Anyway, an impact gun does make it easy. All the ones I've hit with one come loose immediately. Swap the pulleys, remembering the spacer, and tighten it up. You are done.

Gary, AKA "Gary fellow": Profile

86-350-460-dually

Re: 3G alternator new or used?

I thought I had remembered something about how the 130 amp alternators were not good on the V belt pullys because of something to do with the belt? I understand you gotta swap the pullys, but other than that, there isn't any concerns going with the 130 amp?

I'm going to hopefully find a 90's taurus tomorrow at the junk yard.

Adam

1986 F-350, Dually 4WD, C/C with the 460/7.5L

Gary Lewis

Re: 3G alternator new or used?

Administrator

A V belt won't transmit enough power to produce more than about 90 amps from what I've read. But it isn't likely you'll ever need that much current, so should be fine. Or, you can do a double-belt arrangement to the alternator, but it takes a bit of searching to find a crank pulley and alternator pulley with the right belt sizes and diameters.

Gary, AKA "Gary fellow": Profile

86-350-460-dually

Re: 3G alternator new or used?

Okay. Thank you for that. So I should be happy with either the 90 or 130 alternator, if I find one tomorrow. Thanks.

Adam

1986 F-350, Dually 4WD, C/C with the 460/7.5L

ArdWrknTrk

Re: 3G alternator new or used?

Administrator

In reply to this post by 86-350-460-dually

86-350-460-dually wrote

I'm curious if that one fits the V belt or the Pully system? I have the V belt system.

None of the 3G alternators were made with V-belt pulleys, so i guess I misunderstood your question.

You are asking if the alternator I linked is 8.25" C-C, which fits a V-belt mounting bracket?

Yes. The 3.8l Taurus engine uses 8.25" mounting.
The 7" center ears do not allow enough adjustment swing to fit the V-belt mounts of the 460 and 300-6 engines of this era

The 3.0l Taurus engine uses the smaller 7" mount that fits the serpentine bracket of the Windsor pickup engines

As for belt slip with the large body (130A) alternator.
I always figured I'd rather have the better cooling diode board, and run it at 75% rated output than run the 90A unit at 100%.
Realistically, unless you have a big inverter or a winch you aren't likely to even stress the small body 3G.

The alternator will only load the belt as much as is demanded of it.
160, 130, 90, 60, any alternator will require similar power input to create similar power output.
The big advantage is that the 130A 3G can put out 65A at idle, where the stock 1 & 2G V-belt alternators need to be spinning much faster, and that is their limit before meltdown.

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.

Steve83

Re: 3G alternator new or used?

Banned User

In reply to this post by 86-350-460-dually

86-350-460-dually wrote

I don't know how to put that stuff in quotes^

Click "Reply", then click the "Quote" button. Then edit down the quoted post to just what you're interested in. If necessary, copy & paste the quote tags to enclose each section that you want to reply to separately.

86-350-460-dually wrote

...a ballpark estimate of the price/alternator...

It depends on local availability & demand (like almost everything else). If the only people buying alternators from that JY are the scrap metal recyclers, prices are likely to be low. If there are plenty of alternators, demand won't raise the price much. But if used alts are popular & scarce, you'll pay more. To see prices in my area, check out:
http://www.pullapart.com/inventory/
http://www.lkqpickyourpart.com/locations/LKQ_Pick_Your_Part_-_Memphis-215/recents/
http://www.upullitap.com/inventory.aspx

For national prices (which are almost always MUCH higher than mine), try:
http://car-part.com/

But you can sometimes find parts MUCH cheaper on CL, LetGo, etc.

Gary Lewis

Re: 3G alternator new or used?

Administrator

In reply to this post by ArdWrknTrk

Jim - I agree with you. But, there is one potential advantage to the 90A alternator - maybe not needing to remove the shunt to the ammeter. Since 70A alternators were available for these trucks, as I've recently pointed out on the Alternators page, the shunt must be capable of that much. Perhaps it could do 90A in a pinch?

As for the 3G's output at idle, you are probably remembering the RJM chart. Do you have a copy of that, or any chart showing 3G output vs RPM? I also added info on the 1G's output to the Alternator page and would like to add the 3G info but can't find it.

Gary, AKA "Gary fellow": Profile

Steve83

Re: 3G alternator new or used?

Banned User

Gary Lewis wrote

...not needing to remove the shunt to the ammeter.

The shunt doesn't really go to the ammeter - it goes to the battery & all the electrical loads. The ammeter is ACROSS the shunt (it reads the voltage developed by current passing through the shunt's resistance, but displays that as an inferred amperage). So regardless of the alternator type (1G, 2G, 3G, 4G, Leece-Neville...), it's a poor circuit design and should be converted ASAP to a low-resistance wire (shorter & without all the connectors) & a true voltmeter. Most especially if you've swapped to a HO alt.

ArdWrknTrk

Re: 3G alternator new or used?

Administrator

This post was updated on .

In reply to this post by Gary Lewis

Gary Lewis wrote

Jim you are probably remembering the RJM chart. Do you have a copy of that, or any chart showing 3G output vs RPM? I also added info on the 1G's output to the Alternator page and would like to add the 3G info but can't find it.

I'm sorry, no I never copied Ryan's pages.

irc Chris was part of the discussion of archiving that site before it disappeared.

Not sure if you could find those charts on the way back machine.
I know I had those URLs bookmarked on my long dead netbook.

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.

Gary Lewis

Re: 3G alternator new or used?

Administrator

Steve - I agree that the shunt needs to be removed if you go to a high-output alternator as they have been known to melt when not removed. I recently replied to a post on FB where a guy said he'd burned his wiring up in that general area and I asked if he'd just done a 3G upgrade. He response was something to the effect of "Yes, how did you know?"

But I'm not sure a 90A 3G qualifies for "high output". That's about a 30% increase over what the shunt is probably rated since the trucks could come with a 70A unit. Perhaps the shunt would handle that? I don't know.

Jim - I'll contact Chris as I played with the Way Back Machine last night and couldn't find what I was looking for. But it would be good to find that chart and add it to the ones showing 1G output vs RPM.

Gary, AKA "Gary fellow": Profile

Steve83

Re: 3G alternator new or used?

Banned User

Gary Lewis wrote

I agree that the shunt needs to be removed if you go to a high-output alternator...

I'm saying the alternator doesn't matter, period. I advise everyone to re-wire the charge circuit like a stock 3G's for better performance, more safety, and more functionality - even with a stock 40A alt.

86-350-460-dually

Re: 3G alternator new or used?

In reply to this post by Gary Lewis

In a twist of events, I do not believe the alternator went out. I haven't had a chance to check the alternator yet because I haven't gotten the truck up and running yet. Had the battery charger hooked up to the battery overnight, but I didn't realize it was only set for 120 min (timer). This morning, the battery was more dead than yesterday. We believe something is driving the battery (a light, a short, something...).

So I 'wised' up and disconnected the battery terminals this time and am trickle charging it all day and night tonight. The battery was so dead, I could not get a voltage reading on it. If I have a fully charged battery, I should be able to get the truck on and check the voltage with it running, and then hopefully search for whatever light is left on (maybe glovebox) or end up searching for some sort of short.

I don't know if I should feel relieved or frustrated haha.

Adam

1986 F-350, Dually 4WD, C/C with the 460/7.5L

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