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3G advice

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Tyler

3G advice

I have spent a lot of time reading about the conversion and have a 130amp alternator and harness in my Amazon cart at this very moment. However, I just need a warm fuzzy that replacing my 1G dual belt little guy with a 130 will be enough to add a decent LED light bar up front and 2 LED lights on my hitch at the rear. I haven't bought the extra lights yet.

My sniper system and fuel pump are zapping too much current for when I have headlights and heater blower on. Just gonna add lights in the near future and will also need to support standard trailer lights.

Thanks guys.

1985 F150 4x4 SB 300 I6: Comp 268 cam, '68 240 head, Offy DP, FI manifolds, Holley Sniper 2300, DUI street/strip distributor, BW T-18, Tuff Country 4" suspension lift, Yukon Offroad hubs + front and rear Duragrip LSD 3.73 ratio, 33-12.5/15s

Gear Vendors overdrive unit on order.

Oklahoma boy livin in Washington State. Retired submarine MMNCM (Nuclear Machinist's Mate, Master Chief)

Machspeed

Re: 3G advice

Administrator

WOW, I've been doing the same thing and was just fixing to post on this when I saw your post. Rather than make another post, hope you don't mind if I add to it!

After a post I made here on a truck fire and the noted frequent fires and associated causes, I am attempting to eliminate all possible causes for a fire. One of those is the 2G alternator for which I’ve read are high on that list for potential fire causes. I still have my original OEM 2G alternator, thus my desire to make the change to the 3G. Know that I do not plan to add much more to my truck in regards to its current electrical load. At best, I may add a small amp to the newly installed stereo and upgrade the headlights. I’ve already don the harness change and added a new light switch.

I’ve read through our resources on the 3G conversion for which Gary and company did an exceptional job. Still, I’m left with questions. Want to start out with just a few and add to it.

My Truck: 351HO, Edlebrock Carb with electric choke, V-Belt system, no power windows or power locks.

1. Am I correct that my current V belt alternator has an 8.25” mount spacing?

2. If so, in the list of donor cars for which one can pull a 3G alternator and associated parts, do all those
have an 8.25” mount spacing?

3. As my truck won’t need much more than the current 2G alternator is supplying, would it matter if I
went with a 90 Amp alternator or a 130 Amp?

John

"Blackie" - 1986 F150 4x4 - Mildly warmed over 351W HO - Original owner

Gary Lewis

Re: 3G advice

Administrator

In reply to this post by Tyler

Tyler - The 130 amp 3G will be far more than enough for what you want to do. Not only will it put out more than twice what your current unit does, it'll put out as much at idle then the current one will.

But I highly recommend that you get one with at least a 2 second delay built in. Even my serpentine belt would chirp on startup as my 3G kicked in to fill the battery up after starting. However, the delayed start regulator fixed that.

On yours with v belts you'll probably have more squeal than I did. So you need the delay even more. And, do your best to stay with the dual belt arrangement.

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

Gary Lewis

Re: 3G advice

Administrator

In reply to this post by Machspeed

John - I'm not an expert here, but I just measured the 1G I have and I found that it is 7" c/c on the bolts. So I'm confused as I would expect your 2G to fit in the same spot. But our page says "* Trucks that currently have V-Belts use the 8.125” mounts, and trucks that have serpentine belts use the 7” mount spacing. (* Need to verify this info)." So I don't have good answers.

Given that, I'm tagging Jim, who seems to have a better handle on this than I do.

Gary, AKA "Gary fellow": Profile

Gary Lewis

Re: 3G advice

Administrator

I just spoke with DB Electric and I was told that they don't sell a 3G with an LRC regulator. Nor do they have the LRC regulator for sale.

It was a long conversation between myself and a very nice lady, who spent a lot of time talking to others at DB. I think she understood what I was asking for but the gurus she was talking to didn't. Finally she talked to a guy that used to build alternators for them and he said the only alternators they sell with LRC regulators are the 6G's, and they won't fit our trucks.

So if you want a DB alternator with LRC you'll have to change out the regulator yourself. It isn't hard, but it adds to the cost.

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: 3G advice

Administrator

This post was updated on .

Gary,
It is because the larger body of the 130A 3G -when combined with- the shorter 'arms' of a 7"C-C puts the alternator too 'deep in the pocket' to give you any appreciable adjustment.

Imagine trying to pass a fat man in a narrow hallway, or something like that.

As for not selling an alternator with LRC regulator. I don't know what to say....
The one I bought recently had one installed.
I had preemptively bought a new LRC regulator, intending to swap it out, but instead it was relegated to the parts box (until you asked for it)

I linked the one I'd purchased noting the fact of the odd packing and that it came with one.

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.

Machspeed

Re: 3G advice

Administrator

In reply to this post by Gary Lewis

Gary, I'm pretty sure that mounting offset is 8.250", will measure it when I get home tonight. I've been doing a lot of study on this via our site and others and I see a lot of people merely wiring these 3G alternators in their trucks with little concern regarding the LRC regulator the ammeter and such. My strength is not in electrical and I want to do this right so I may have a few more questions. As always, thanks!

John

"Blackie" - 1986 F150 4x4 - Mildly warmed over 351W HO - Original owner

ArdWrknTrk

Re: 3G advice

Administrator

In reply to this post by Machspeed

Ok, I got the mail and am responding:

No, your 2G is going to be 7" C-C, but the body diameter is likely 130 mm (like the 95A version of the 3G.
The 130A 3G is 148 mm and with the short 'arms' won't leave you with much tension adjustment.

It is the 3.8 V6 engines found in early '90's Taurus/Sable/Lincoln that will have the 8.25" mounting.
If you want a 7" 130A look at the 3.0 models

I don't know much about the 95A versions, as found in the mid-'90s trucks.
I wanted the better cooling and the bigger diode board found in the 130A version, more than any need for that much output.
I will say if you're considering an electric cooling fan the 130A should be installed.

Having the truck charging at idle was my bigger concern, given that in winter I often have my lights and blower running.

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.

ArdWrknTrk

Re: 3G advice

Administrator

This post was updated on .

In reply to this post by Gary Lewis

Gary,
I want to point out that you have a 2 second response and a 6 second ramp up, as confirmed by Rusty in your thread.

But the last time I ordered from DB my boxes came labeled "J&N Electric".
That alternator had the same regulator that I sent you, and you have the data sheet to prove it.
**at least it has the same number as the one I sent you**

I called my order in to DB Electrical in Tennessee, so I'm quite sure I didn't get 'counterfeit' from Amazon.

**edit**

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.

ArdWrknTrk

Re: 3G advice

Administrator

In reply to this post by Tyler

Tyler,
With V-belts you're going to find them slipping much over 100A draw, but your lack of charge at low revs will stop.
That's exactly why I installed mine, and it eliminates any issue there.

Gary is correct in saying that a 130A 3G will put out more at idle (if asked to) than the 65A a 2G puts out at redline.

Your 1G could be as anemic as 35A, but I don't know which version you have installed.

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 advice

Administrator

In reply to this post by ArdWrknTrk

Jim - All I know is what I'm told. But I didn't think what I was told made sense.

So I searched and found that you posted about your alternator here, and it is an AFD0028 from DB Electric. If it has LRC then it is the one I'd go with.

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: 3G advice

Administrator

Perhaps im not making any sense?

Gary,
I sent you the alternator test sheet when I sent the starter test sheet.
You'll see it has a graph like a daisy.

On that page it outlines that the Load Response Control as having 2 second response and six second ramp.
IIRC, it even has a chart over time showing that.

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.

Tyler

Re: 3G advice

I canceled my Amazon order for a different model but it shipped anyway so I will return it when it gets here. Today I'll order the model Gary linked above.

Much appreciated everyone!

Gary Lewis

Re: 3G advice

Administrator

In reply to this post by ArdWrknTrk

Jim - We have the test results, but not the chart, on the page at Documentation/Electrical/Alternators. I've now added links to the DB page where they are selling the AFD0028 as well as to that page with the test results to the 3G page so I don't forget again.

As for the test results, here is a snippet where I circled the 4.5 second soft start delay and the 2 second load response control:

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: 3G advice

Administrator

That's really odd.

Either the sheet is false, or the regulator that came in the alternator is.
Because 1+2=/=3 in this case.

I wondered why these have come in J&N packaging recently.

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.

Machspeed

Re: 3G advice

Administrator

In reply to this post by ArdWrknTrk

ArdWrknTrk wrote

Ok, I got the mail and am responding:

No, your 2G is going to be 7" C-C, but the body diameter is likely 130 mm (like the 95A version of the 3G.
The 130A 3G is 148 mm and with the short 'arms' won't leave you with much tension adjustment.

It is the 3.8 V6 engines found in early '90's Taurus/Sable/Lincoln that will have the 8.25" mounting.
If you want a 7" 130A look at the 3.0 models

I don't know much about the 95A versions, as found in the mid-'90s trucks.
I wanted the better cooling and the bigger diode board found in the 130A version, more than any need for that much output.
I will say if you're considering an electric cooling fan the 130A should be installed.

Having the truck charging at idle was my bigger concern, given that in winter I often have my lights and blower running.

Jim, how'd you get so dang smart and versed over such a wide range of stuff! You were exactly right, 7" C-C.

I'm left a bit confused regarding your comment regarding the short arms and tensioning. Are you saying I'm limited to the 95 amp 3G alternator with my current V Belt configuration? If so, I'm fine with that, this is more about fire hazard than having all that amperage. Gonna pull one from a salvage yard with harness and all. Can you advise/clarify on best vehicle to pull from?

John

"Blackie" - 1986 F150 4x4 - Mildly warmed over 351W HO - Original owner

ArdWrknTrk

Re: 3G advice

Administrator

I'm not smart, I'm autistic.
You know that kid who knows everything about apatosaurs? yeah, that's me.

Except I'm intersected in electrons.

7" C-C means 3 1/2" radius to the mounting and pivot bolts.
8 1/4" mounting means 4 1/8" from the center to the center of the mounting bolt.
The 95A 3G (and likely the 2G) is around 5 1/4" diameter, where the 130A is almost 5 7/8" (148mm)

So, if you took a 5 1/4" circle and marked a 3.5" radius and a 4.125" radius
Then you did the same with a 5 7/8" circle at both radii you could visualize how many degrees each circle would fill from the vantage of the pivot bolt.
And, by moving the alternator body away from the block it gains even more room to swing.

My mind doesn't see things the same way as neurotypicals.
Im sorry if it is difficult for me to make a good analogy.

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.

Machspeed

Re: 3G advice

Administrator

Jim, what would be your recommendation for an alternator for my truck....LOL!

John

"Blackie" - 1986 F150 4x4 - Mildly warmed over 351W HO - Original owner

ArdWrknTrk

Re: 3G advice

Administrator

The alternator I've used fits well.
It also has the smaller 8x1.25 adjuster hole, so you can just run a 3/8-16 tap through. (No need to helicoil the larger 10mm hole down to work)
You'll need to take a little of the offset out of your curved adjuster bracket.
I think the boss on the 3G is a 1/4" thicker.

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.

Rusty_S85

Re: 3G advice

In reply to this post by Tyler

Tyler wrote

I have spent a lot of time reading about the conversion and have a 130amp alternator and harness in my Amazon cart at this very moment. However, I just need a warm fuzzy that replacing my 1G dual belt little guy with a 130 will be enough to add a decent LED light bar up front and 2 LED lights on my hitch at the rear. I haven't bought the extra lights yet.

My sniper system and fuel pump are zapping too much current for when I have headlights and heater blower on. Just gonna add lights in the near future and will also need to support standard trailer lights.

Thanks guys.

Honestly I think your stock 1G would be enough for a LED light bar and two LED lights on your hitch.

I am using my 1G stock alternator on my truck which I will upgrade to a 3G but I have composite ECE headlights installed with silverstar Ultra H4 halogen bulbs, a pair of Apollo 6" 100w H3 halogen driving lights and have no problem powering that setup of lighting. I doubt a LED light bar you are looking at and two LED hitch lights would be pulling more amps than my light arrangement. I also doubt it would pull more than my planned light arrangement which is why I want the 3G where I will be adding another 400w worth of lighting on a bed bar.

But with a 3G 130A is well over enough. I keep struggling with the upgrade myself as I really want the 95A unit which would still be well over enough for me but would allow me to have a properly sized megafuse for my charging circuit, but the ear spacing isnt enough to properly fit and make fitting the OE alternator belt troubling. I will just have to go with the 130A I think and plan on running a 100A fuse cause there is no way a single V belt is going to burn up a 3G 130A alternator, belt would slip and get thrown off or melt in two before a properly sized 130A 3G mega fuse would pop.

"Old Blue" - '56 Fairlane Town Sedan - 292-4V, Ford-O-Matic transmission, 3.22:1
'63 Belair 2dr sdn - 283-4V, Powerglide transmission, 4.56:1
'78 Cougar XR7 - 351-2V, FMX transmission, 2.75:1 9inch
"Bruno" - '82 F150 Flareside - 302-2V, C6 transmission, 2.75:1 9inch, 31x10.50-15 BFG KO2

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