Quick Question about Alternator Replacement

[panic29505]

Quick question that I couldn’t find in any of the searches I did, apologies if I missed it before.

I want to replace my alternator. It’s been through a lot and seems tired. I’ve replaced the belt and tightened it like crazy and still have a raging squall. Current alternator is 1G and I want to replace with a 1G with higher output (75A) do I have to change anything about the voltage regulator? I don’t have the time to work on any wiring issues right now but want to get this alternator issue handled now. I don’t really run anything inside the truck off the electrical system (I use an external Bluetooth speaker, leave the radio off, and only heater on occasion…I want to keep this Bronco simple and fairly close to original so I don’t see the need for a 3G upgrade at this time).

Thanks in advance for your time,
Kevin

 

[Steve83]

A 3G always makes more sense than a 1G or 2G, but all 1Gs use the same VR.

(click this text)


(click this text)

 

[DirtDonk]

Hey Kevin. What year is your bronco?
Does it have an Thermactor (air pump)?
Do you want a specialized custom output 1G with the same size case, or do you want to upgrade to the larger case unit?
Reason for that last question is that in the old days at least (I haven’t looked lately) the standard case 1G maxed out at 65A. The lowest output 1G large case, which is what I used on my 71, is 70 to 75 A.
That said, even though it’s larger, it fits with no problem as long as you have the standard alternator bracket without the air pump.
However, there is a minimal amount of rewire involved.
If you have an original tall case voltage regulator, you may have to upgrade to the later model, integrated circuit type that FORD started using on the Granada, in about 73 or so. Then eventually on everything until they went internal.
The rewiring is as simple as splicing a new connector onto the end of wires.

And last, but perhaps the most important, what’s the condition of your existing wiring? The stock 10 gauge charge wire is sufficient, but only if it’s in really great shape.

 

[DirtDonk]

And Steve is correct that the 3G is a great way to modernized the charging system.
The small 95a version is an easy fit under the same conditions as my description previously.
But it involves a lot more rewiring, which you said you didn’t really want to do.

 

[DirtDonk]

I guess the only way to do it with no rewire at all, would be to get another small case 1G (as you were planning) but with the higher output.
I wouldn’t go more than 70a output, though, unless you do some more upgrading.

Have you been looking recently and have found some higher amp output models? Not surprising if they do

But since your main problem is squealing, and you didn’t say that it wasn’t charging the battery, have you tried cleaning the pulley with solvent and sandpaper?
You said you changed the belts, but you need to change the pulley too. Or at least clean them really, really good.
After all, the more output you add to the Alternator, the more load is on the belt and pulley. Going bigger is not necessarily going to reduce belt squeal. Usually the opposite in fact!
And many new alternators come without a new pulley. Reusing your old one would probably just reintroduce squeal, but more of it.

 

[panic29505]

Dirt, and Steve, thanks so much for taking the time to help me out. My bronco is a 76 and I am going to try and include some pics to this post. I’ve had some issues with dead batteries but I attributed it to not driving it regularly (recently added a battery charger in hopes to eliminate that and extend the life of my battery)…then, this week the squeal got really bad and I had a totally dead battery. I changed the belt and got it home. I tightened it as much as I could but ultimately, I want to put some dough and time into the bronco in hopes of making it significantly more reliable. I had a decked out frame off 65 mustang and never drove it because it was too nice. I’m also trying to fight my natural tendency to drop a bunch of money and do it all at one time…most because I don’t have the money and I really want to try and learn how to work on and care for this bronco.

When I started looking into what I had and what I wanted to do I found a PowerMaster 1 wire (looks to be a direct drop in replacement) but puts out 55A (idle) 75A (Running) I don’t run a stereo or really any other things inside the truck off the electrical and never plan to add a stereo or additional lights. I do not have an air pump or a specialized high output alternator (that I know of, it’s the alternator that was on the bronco when I bought it). I didn’t know about the pulley change but could try that and see. I’m just of the mind that if it’s towards the end of it’s life I’d rather replace it now and not get left on the side off the road and if I can get a little more performance from it, all the better.

Clearly I’m a beginner but really want to learn about my Bronco and do as much of it as I can. When I read about the voltage regulator changes from 1G to 3G and it involving wiring harness stuff I backed off. I hate wiring issues and I just don’t’ have it in me right now to take that on.

Thanks again fellas. I really appreciate your time. It’s nice to come to one spot and get some good solid information especially information specific to Broncos. I’ve been reading forum posts forever but finally dipped my toe in to ask for some help.

Kevin

 

[gnpenning]

Kevin, how often are you driving the Bronco?
What type of belt did you buy for a replacement? Yes, it makes a difference. If the belt or pulley gets glazed it's hard to get traction and not squeal. Width is as important as length as well.

Do you have a dvom or test light? If not buy both. You don't need high dollar ones, $20-30 for both should do everything you need for now. If needed watch a few videos on how to use them for automotive. I would suggest you pull the battery negative cable and put a test light in series and see if it lights up. You can turn on the park or headlights to see if it's working if you are unsure. Report back.

I would suggest to pay the $12 to become a contributor. It will make posting pictures easy. Even I can do it. There are other ways but this is the easiest for most people.

 

[DirtDonk]

Sounds like a reasonable beginning to your refreshing the Bronco Kevin. It’s fun to upgrade and spend money, but it’s also just as rewarding to make what you have the best it can be.

In the instrument cluster is an ammeter, which tells you whether the battery is being charged or discharged or not.
It’s good to keep an eye on it to see if yours actually works. And if so, just what is going on in the electrical system.
Voltmeters can do the same thing. But you currently have an amp gauge/ammeter, so see if it can help diagnose your situation.
Most Early Bronco ammeters still work, while most other vehicle ammeters have long since died or never gave good information to begin with.
Ours just happened to be one of the best out there, when they were new.

You will probably see the ammeter needle climb towards the charge state farther when the squealing gets louder. When you simply turn the key on or to accessory, you should see the needle twitch a little to the negative side. Turn the headlights, flashers, heater motor, and you’ll see it go further into the negative.
Once the engine is started, if your Alternator is still healthy, it should immediately go to the positive side and then slow slowly go down more towards zero again once the battery is fully charged.

As GN said, if the vehicle sits for a long time, it could just be the battery or a small parasitic loss. But if it goes dead quickly, it can be other things, including a bad alternator or regulator or ignition switch. Take your pic sometimes!

More testing to do, but in reality there’s nothing wrong with putting a new alternator on anyway.
Just know that here we usually recommend against throwing parts at a problem until you know what’s going on.
The squealing belt doesn’t mean the alternator is bad and needs replacing. And as you will hear or probably have seen already, most of us are skeptical about the quality of new parts no matter how expensive or how highly touted they are.
Sometimes older is better.
Certainly, alternators do go bad. And old 1G alternators, especially if they’ve been replaced with a rebuilt unit, tend to go bad sooner than some others.
But we still recommend against automatically replacing.

You certainly don’t need a more powerful unit, it sounds like. But one that puts out a decent amount at idle is good. The old 1G units didn’t do much at idle, but Broncos don’t always need much either.
The one you specified sounds like a potential replacement, although I’m skeptical of some 1-wires without seeing it.
Many are based off of GM alternators so while they might be a fairly simple bolt on, they’re almost never completely without some minimal rewiring.
If you have a link to the one you’re looking at, that would be good for us to look at.

 

[Steve83]

...the 3G is a great way to modernized the charging system.
...
But it involves a lot more rewiring...

1 wire has to be spliced: the LG/R. Then the 3G harness plugs in to that, and its ring goes on the starter relay. That's not much rewiring.

(click this text)

...I want to put some dough and time into the bronco in hopes of making it significantly more reliable.

You're describing the 3G swap.

...1 wire (looks to be a direct drop in replacement)...

The normal 3G alternator has 2 wires: the big power output, and the LG/R.

...if it’s towards the end of it’s life I’d rather replace it now and not get left on the side off the road and if I can get a little more performance from it, all the better.

Again, that's the 3G swap, which is all Ford.

When I read about the voltage regulator changes from 1G to 3G and it involving wiring harness stuff I backed off. I hate wiring issues and I just don’t’ have it in me right now to take that on.

Where did you read that? If you grab the harness in my pic above from a JY, with the pigtail for the LG/R wire off the donor vehicle's engine bay harness, you simply splice that LG/R pigtail onto your Bronco's original LG/R wire, and then it's PnP. Put the rings on the alternator & starter relay, plug in the VR , tape up the unused Bronco wires, and it's done. Installing a stereo is harder. Installing a headlight relay is harder. Installing a USB charging socket is a little easier, but not by much.

I know you're gonna do what you want to do to your Bronco, and that's fine. But your reasons for NOT doing the 3G swap are misinformed.

 

[BronCowie]

3G one wire has worked great for me since 2014!

 

[panic29505]

Sounds like a reasonable beginning to your refreshing the Bronco Kevin. It’s fun to upgrade and spend money, but it’s also just as rewarding to make what you have the best it can be.

In the instrument cluster is an ammeter, which tells you whether the battery is being charged or discharged or not.
It’s good to keep an eye on it to see if yours actually works. And if so, just what is going on in the electrical system.
Voltmeters can do the same thing. But you currently have an amp gauge/ammeter, so see if it can help diagnose your situation.
Most Early Bronco ammeters still work, while most other vehicle ammeters have long since died or never gave good information to begin with.
Ours just happened to be one of the best out there, when they were new.

You will probably see the amateur needle climb towards the charge state farther when the squealing gets louder. When you simply turn the key on or to accessory, you should see the needle twitch a little to the negative side. Turn the headlights, flashers, heater motor, and you’ll see it go further into the negative.
Once the engine is started, if your Alternator is still healthy, it should immediately go to the positive side and then slow slowly go down more towards zero again once the battery is fully charged.

As GN said, if the vehicle sits for a long time, it could just be the battery or a small parasitic loss. But if it goes dead quickly, it can be other things, including a bad alternator or regulator or ignition switch. Take your pic sometimes!

More testing to do, but in reality there’s nothing wrong with putting a new alternator on anyway.
Just know that here we usually recommend against throwing parts at a problem until you know what’s going on.
The squealing belt doesn’t mean the alternator is bad and needs replacing. And as you will hear or probably have seen already, most of us are skeptical about the quality of new parts no matter how expensive or how highly touted they are.
Sometimes older is better.
Certainly, alternators do go bad. And old 1G alternators, especially if they’ve been replaced with a rebuilt unit, tend to go bad sooner than some others.
But we still recommend against automatically replacing.

You certainly don’t need a more powerful unit, it sounds like. But one that puts out a decent amount at idle is good. The old 1G units didn’t do much at idle, but Broncos don’t always need much either.
The one you specified sounds like a potential replacement, although I’m skeptical of some 1-wires without seeing it.
Many are based off of GM alternators so while they might be a fairly simple bolt on, they’re almost never completely without some minimal rewiring.
If you have a link to the one you’re looking at, that would be good for us to look at.

Thanks so much for such a well written and well thought out response. That all makes sense to me. My nonbronco life got in the way the last few days and I am just getting caught up. I take your advice and your points as they are all good ones. I’ll report back, but I am rethinking after reading your post. Thanks again so much for helping a stranger out. I appreciate you.

 

[panic29505]

3G one wire has worked great for me since 2014!

View attachment 952682 View attachment 952683

Such a nice clean setup and I’m jealous of how clear your pics are. I’m going to try to post a few pics myself just for reference…please excuse the quality.

 

[panic29505]

1 wire has to be spliced: the LG/R. Then the 3G harness plugs in to that, and its ring goes on the starter relay. That's not much rewiring.

(click this text)


You're describing the 3G swap.

The normal 3G alternator has 2 wires: the big power output, and the LG/R.

Again, that's the 3G swap, which is all Ford.

Where did you read that? If you grab the harness in my pic above from a JY, with the pigtail for the LG/R wire off the donor vehicle's engine bay harness, you simply splice that LG/R pigtail onto your Bronco's original LG/R wire, and then it's PnP. Put the rings on the alternator & starter relay, plug in the VR , tape up the unused Bronco wires, and it's done. Installing a stereo is harder. Installing a headlight relay is harder. Installing a USB charging socket is a little easier, but not by much.

I know you're gonna do what you want to do to your Bronco, and that's fine. But your reasons for NOT doing the 3G swap are misinformed.

Steve, thanks for taking the time to post all of that and share such good information. I see what you are saying about it being minimal wiring and I‘m going to give it some thought. Do you or anyone else have any recommendations on a good dependable 3g to Consider? Thanks for the info on where to get the wiring harness. I appreciathe that. I’m going to try and upload a picture of two of what I’m working with…maybe that will help. Thanks again for your time. I really appreciate it.

 

[panic29505]

Kevin, how often are you driving the Bronco?
What type of belt did you buy for a replacement? Yes, it makes a difference. If the belt or pulley gets glazed it's hard to get traction and not squeal. Width is as important as length as well.

Do you have a dvom or test light? If not buy both. You don't need high dollar ones, $20-30 for both should do everything you need for now. If needed watch a few videos on how to use them for automotive. I would suggest you pull the battery negative cable and put a test light in series and see if it lights up. You can turn on the park or headlights to see if it's working if you are unsure. Report back.

I would suggest to pay the $12 to become a contributor. It will make posting pictures easy. Even I can do it. There are other ways but this is the easiest for most people.

If I become a contributor, can I just drop pics into a post? I tried to do it again just now but the only way I see how is by using a url, and they are just pics on my camera roll. Sorry to hit you with so many rookie questions. I’m trying thought

 

[Broncobowsher]

Yes. Easy drop in pictures. No links that people avoid clicking on. Mine is expired. When I need to post pics I renew for a year, pic heavy posts. Then slack again until I need pictures again

 

[gnpenning]

If I become a contributor, can I just drop pics into a post? I tried to do it again just now but the only way I see how is by using a url, and they are just pics on my camera roll. Sorry to hit you with so many rookie questions. I’m trying thought

Yes, posting pictures is super easy. I hope someone will post a link. My phone won't let me. Jon, the mod does a good job and will get you posting quickly, well normally.

Don't worry about asking questions. As you have already seen you have gotten support.

 

[Steve83]

...recommendations on a good dependable 3g to Consider?

The reason the 3G is so popular is that it's reliable. As with most parts, the most reliable you can get is genuine Ford. When I can't find a good one in a JY (which is rare), I buy this for my '93-97 trucks (which is NOT the style you'd need with V-belts):

Amazon.com: Motorcraft GL8779RM Alternator Assembly : Automotive

Buy Motorcraft GL8779RM Alternator Assembly: Alternators - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

You'll have to shop for the style (front case shape/mounting bolt pattern) that best fits your engine bracketry. There are at least 4 shapes: 3-bolt (the one in that Amazon link), modular (2 bolts at the bottom), narrow-spread (2 across), and wide-spread (2 across like BronCowie's). This is narrow (note how close each bolt hole is to the body) probably from a '94 T-bird:

(click this text)


This is modular on a '00 CV:

(click this text)


Whether or not you pay ClassicBroncos.com, you can upload pics & videos to SuperMotors.net free and post them in most forums using the provided markup on each SMN page. I manually add the "(click this text)" so that the link will work on phone apps. But SMN is best-viewed on a fullsize monitor.

 

[Broncobowsher]

My spec is a '92 Aerostar with the 3.0 V6. Swap the pulley (and spacer behind pulley if there is one). The threaded bolt hole for the adjuster is a common metric thread instead of SAE. M8x1.25

If you look at the front of a 3G there are 3 spokes in the housing. The spokes will have either 2 holes or 4 holes per spoke. The 130A is the 2-hole. The 90A is the 4-hole. The 130A requires voodoo to make it not squeal with a V-belt. The 90A should be good, I've had good luck with a single V-belt running quiet.