Alternator Upgrade

[norm02]

I’ve been thinking about upgrading the alternator on my Bronco and going to a 1 wire set up. It seems like this can be accomplished by swapping over to a GM 1 wire alternator or by purchasing one of the ones offered by some of the Bronco venders.

The GM 1 wire seems to be about $100 less than what I’ve found on the Bronco vender sites. That’s a fairly large difference in price (given what we’re talking about) so I’m curious as to whether or not there are any benefits to justify the additional cost between the two alternators.

For reference, my Bronco is a ‘66 Roadster and it has a 170ci in it. I’m not running any auxiliary lights and I don’t currently have a working radio in it but I’m planning on adding one in the future. It will likely be comprised of a new head unit and a few speakers. No amps or subs. The only other modification I’m planning on making is upgrading the ignition system to either a DSII or a DUI and I may switch to FiTech down the road.

That being said, how much output do I need given what I’ve mentioned above? I would prefer room to grow VS getting the bare minimum.

Edit: I apologize if this has been talked about already and I did do a search on this site before creating the new thread.

 

[Timmy390]

Been a while since I looked at doing this but a Ford 3G fits in about anything including my 69 Mustang.

Check out this thread for all good info on the swap and what to look for in the scrap yard.
http://classicbroncos.com/forums/showthread.php?t=238216

I upgraded when I did my 351W. Very easy upgrade.......

Tim

 

[B RON CO]

Hi, the Bronco came with a 35 amp alternator.
Ford put a 65 amp alternator in the big cars.
I got the 65 amp and electronic voltage regulator and I do fine. I think it will run everything you mention except the FI tech.
Good luck

 

[Master Chief]

Look at a Powermaster alternator if you are just wanting an upgrade in amperage from stock. American made and direct bolt in.

https://www.jegs.com/i/Powermaster/713/57078/10002/-1

This is their catalog, check out page 7. http://www.powermastermotorsports.com/catalog.html

 

[DirtDonk]

I don't know about the other Bronco vendors Norm, but our 1-wire is not a GM alternator. It's simply a slightly modified Ford 130a 3G unit.

Your needs for power are not that great, so a 65a unit would be good there. But clean power with lots of headroom is very desirable for what you're planning (modern electronic upgrades like EFI) for future mods, so I'd say 90a at least in this case.
The stock style unit Ron mentioned would be a straight bolt-on, need no additional wiring or other changes, and would likely keep your battery very happy for a long time. But I think a newer design is more desirable in a few ways anyway (even though I happen to use an older 70a 1G and love it) and can simplify the wiring even further.

Because you have a 170, I would almost say that the smaller 3G Ford (90a) is a better choice for having less mass to spin up. Which in this case, seems to give the GM 1-wire the same advantage as well. They're usually smaller in size outside at least, so presumably also have less mass to turn inside as well. Toss-up in this case.

I never really liked true 1-wire alternators put out by GM because most of the ones I was used to back in the day were finicky and I did not like having to rev the engine up to get it going and the regulators seemed to fail regularly. I don't think that's so much of an issue anymore, but it sure was in the early days of their use.
A 2-wire version is much more in line with my thinking, because it's working as soon as the engine is idling. Not that this is a huge deal-breaker of course. Just that I like it better. Advantage Ford 3G (for me).

But you can't argue with a 1-wire's simplicity! That's why we carry that 1-wire 3G in fact. And I doubt that any of us selling Ford alternators could ever compete with big-box pricing on a GM product. It's just not the same boat when it comes to the aftermarket. A cheap GM alternator is probably half of what a cheap Ford alternator costs.
So for once I can't argue against a GM product on a Bronco. But I still won't put one on mine when there are better Ford products out there for my use. Even if they cost more up front. Advantage GM, but not enough to sway me personally.

Either one would work in your case, so a 90 or 100 amp alternator would be a great upgrade.

Paul

 

[Timmy390]

I just did the GM upgrade on my Samurai and what you state above about the GM 1 wire is very true. No power output at idle. I went with a 2 wire CS130 105amp and it rocks at 800rmp idle which is needed if you happen to have big lights driving around the hunting lease at night ideling up and down hills.

Tim

 

[weekend warrior]

Here is a good read on the pros and cons of both.
http://www.madelectrical.com/electricaltech/onewire-threewire.shtml

 

[DirtDonk]

Hey, great link! Thanks, haven't seen them referenced in a long time, but they had some good info back in the day.
I did try to by some of their insulated terminal blocks back in the day though, and like they warned, they may not return e-mails or messages. And they don't always get around to filling orders either.
But they do still have some good reference material.

Same reason I enjoy hitting the archived pages of Ryan McCormack's old Ford Fuel Injection/RJM/OldFuelInjection stuff. Some great info thereabouts.

Paul

 

[blubuckaroo]

Hi, the Bronco came with a 35 amp alternator.
Ford put a 65 amp alternator in the big cars.
I got the 65 amp and electronic voltage regulator and I do fine. I think it will run everything you mention except the FI tech.
Good luck

What is it about that fuel injection that requires so much amperage?

 

[Rustytruck]

I used a small case 95 amp 3g alternator found on the v6 cars and small vans. Much easier on the v-belts. No silly belt squeal. Plenty of amps at idle. Much better than the stock ford 1g.

 

[B RON CO]

Hi, modern computerized cars need more current then the original Broncos because a newer car runs a computer, full time electric fuel pump, electronic ignition, and more. The old Bronco with a points and condenser ignition will run for days on just the battery. A modern system will crap out in no time on less than @11 volts. Modern cars come with bigger alternators.
Good luck

 

[englewoodcowboy]

My professional opinion on 1 wire alternators is not to use them. Sure they are easy to connect, a caveman can do it but so is a 3 wire system. The main reason I do not like them is the fact that in this day and age of high quality imported crap, we have a 1 in 6 failure rate of brand new Bosch alternators. No 2 have had the same failure back to back but the sad truth is there are only a few companies that manufacture the critical components like the rectifier, voltage regulator or bearings. I have yet to have a bad case or stator but they simply don't make the parts that typically fail and it is the same pool most are built from today. So I told you that to make this point, if you go 1 wire and you are out of town having a good time and it quits, chances of finding one at the local parts house is slim to none whereas an OE replacement is much more likely or they can have one in in just a few hours. This is my biggest concern, not over simplicity but reliable parts securement when it fails and that being able to readily find one vs. having to lug around a spare for that "what if" is the biggest factor I don't want to deal with. If it breaks I want to fix it and keep on having fun, not be down for a weekend while we await a UPS package...

 

[Broncobowsher]

You are not needing much for power. Drop a stock 60A alternator with upgraded electronic voltage regulator and be done. More output than you will use, not so much to overwhelm the stock wiring. Easy bolt in parts.

 

[bamabaja]

Good articles and comments. I will need more juice on Offroad build for EFI, lights, etc. and leaning to 3 wire setup. As usual a lot of vendor choices out there with expected hype. Any thoughts on quality brands to consider? Thanks

 

[bmc69]

Go big or go home.... I'm running a Leece-Neville 1-wire on my '78 Bronco. It's a beast..although it's rated output is 165A, it's designed for emergency vehicle service and puts out 80A at fast idle.

Pic of it next to stock Ford alternator...and the output curve.

My '78 is set up as a SHTF/pack-it-in camping rig with twin 1000cca batteries and a 4000w power inverter.

 

[blubuckaroo]

You are not needing much for power. Drop a stock 60A alternator with upgraded electronic voltage regulator and be done. More output than you will use, not so much to overwhelm the stock wiring. Easy bolt in parts.

Also, you can keep your ammeter when your alternator can't feed an overload through the stock wiring.

 

[DirtDonk]

Computers don't use much current. But they don't like low-voltage situations much either. So higher output alternators "can" be a benefit.
Like they said, your basic 60a with a good regulator can do just fine if you're running an otherwise stock load on your Bronco.
If, on the other hand, you've added other electrical draws and like to go camping and maybe run your system down overnight with things like lights, radios and refridgerators, keeping a good working high-output alternator in the system, with as BIG a battery as you can fit under your hood are both very good things.

Everything electronic likes a good clean strong signal to work with. Hence our harping all the time on making sure you have more-than-sufficient grounds (more like a modern car, or truck), heavy enough gauge wires so that losses are minimal throughout the entire system, and every connection is clean and tight.
With as little errant "noise" as possible too.

Many people have run afoul of their old ignition boxes or tired plug wires interfering with the happy workings of the EFI computers.

Paul

 

[Rustytruck]

The benefit of the newer high amp alternators is not the high amps at high speed, its the higher amperage at idle speeds. It gets much more steady power at slow speed. Something the old stock system wasn't very good at.

 

[blubuckaroo]

The benefit of the newer high amp alternators is not the high amps at high speed, its the higher amperage at idle speeds. It gets much more steady power at slow speed. Something the old stock system wasn't very good at.

So then why would the average owner pass over the 95 amp model like yours and go all the way to a 130+?
The problem I see is, say you have to crank the starter longer than normal for some reason. When that engine starts, that large charging load is there immediately. That's why so many have had to go to double pulleys and serp belts. Also, you had better increased your battery cable size accordingly.

An alternator is clearly a case where the biggest isn't always better.

 

[weekend warrior]

I went with a 130 amp mustang 3 wire and a PA Performance voltage regulator. Don't forget to put an in line 150-175 amp fuse or breaker between your alternator and solenoid. I found the alternator on ebay. USA built with a lifetime warrantee for $55.00.

https://www.paperformance.com/1g-3g-conversion-462802c/

https://www.ebay.com/itm/FORD-MUSTA...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649