So was wondering if/how it's possible to put a higher output alternator on my 84 Bronco? I've heard of it being done before just not sure what year/model to get an alternator to get and if any wiring upgrades are needed to the pigtail or voltage regulator (I have an external one now) areneeded.

 

So was wondering if/how it's possible to put a higher output alternator on my 84 Bronco? I've heard of it being done before just not sure what year/model to get an alternator to get and if any wiring upgrades are needed to the pigtail or voltage regulator (I have an external one now) areneeded.

 

Hi Hayden,
Yes there is.
I put a 130amp 3G alternator into my '85 Bronco.

I got the alternator out of a 1995 Ford Windstar with a 3.8L V6. This is a perfect fit for the '80 - '86 as it has nearly the same bolt pattern.



If your current alternator only has a single belt, you'll want to source a dual belt pulley, as the 3G takes a lot more effort to spin. Otherwise, it'll squeal.



I got mine from a junk yard and then had it bench tested at an autoparts store before putting it in. They're a pricey alternator new, so used is a good way to go since they last a long time.
You'll also want to grab the big 8 gauge wire that goes to the fuse box that has the fusible link in it. You'll run this from the alternator to your battery positive. It needs to be a big wire to handle all the juice.





(You can see the orange and black wire if you look closely. It turns into a dual wire fusible link that is going to the left side of the starter relay)


It's internally regulated, so you can remove all of your 1G alternator wiring. The only thing you'll want to save is the plug on the right as well as a length of the big yellow wire from it. You'll see why below.




One thing to note is that you do NOT want to hook up your ammeter in the cab. It'll fry it. You can have this converted to a voltmeter if you want to restore it to working again. There's some places online that'll do it. I haven't done it yet.

One thing to note is that when you remove the stock wiring for the voltage regulator, you will lose power to the cab. It's all tied together in some really wonky wiring splices.
This is the wiring diagram for the 1G



Here's the diagram for the 3G




The 3G wiring is extremely simple. Most of it connects to itself.

To restore power to the cab, find the original plug with the big yellow wire and connect that to direct power (this is the power to the cab).
Then, run the green/red (LG/R) wire to the green/red (LG/R) wire on the 3G and it should be good to go. The plug will have 2 other connections on it that you can leave disconnected. They're for the ammeter.
Like this:







Hopefully that helps. I know pictures can be a little confusing, but I think they'll make sense when you get in there and start looking at it.
It's a very worthwhile upgrade.

 

Welth of information and how to, thank you! This will probably be my next project on the beastie.

Hey Mods, should this be stickied somewhere?

 

My pleasure!
I've been meaning to do a writeup on it, so maybe I should do a formal one.

 

You can always do a single wire conversion with an aftermarket unit. There a a few companies out there making OEM-style retrofit units that allow you to lose all of the external regulator wiring and nly concern yourself with the charge cable between the alternator and the battery. I'd name names but when I do I get slapped for "advertising". So, lt your favorite search engine do the research for you.