All Small Six Generator to 1G Alternator Conversion

[65MustangI6]

I’m swapping my 1964.5 Mustang from a generator to a 1G alternator and wanted to run it by the group to make sure my wiring plan is correct.

I’ve already made the physical swap of both the generator and external voltage regulator. I’ve also purchased the 1G alternator wire harness and a new regulator pigtail. Rather than purchase a different harness I was looking to use existing wires in my current harness.

As you can see from my hand drawn diagram, I’m planning to reuse the black/yellow wire from Harness #100, butt splice it to the yellow wire coming from the A terminal pigtail on the regulator and then carry the black/yellow wire forward to the new alternator harness and up to the positive side of the starter solenoid. The existing black/yellow is a larger diameter wire, so I don't see any issues with that.

For ignition, I’m planning to reuse the yellow/black wire from Harness #100 and butt splice it to the green/red wire on the I terminal pigtail on the regulator. Same as above, the yellow/black is also a larger diameter wire.

The F, S, and G wiring is straight forward and I would use the existing white (field) and black/red (ground) wires that are part of the existing harness. I would need to add a new white/black (stator) wire to the harness. I would run all three from the regulator to a new triple bullet connection to mate with the new alternator wire harness.

Does that all make sense? More importantly, is it right? Is there a better way? Any feedback is always appreciated.

 

[alwill923]

I know this is to late but might help someone else. I installed 10si alternators on my 65 truck and 1960 falcon. They have internal regulators so this eliminates the voltage regulator and wiring. Also inexpensive and available at any FLAPS.

 

[65MustangI6]

I know this is to late but might help someone else. I installed 10si alternators on my 65 truck and 1960 falcon. They have internal regulators so this eliminates the voltage regulator and wiring. Also inexpensive and available at any FLAPS.

Thanks alwill923. I was thinking of going to a one-wire alternator set-up but had this alternator and regulator from a 1966 Mustang on the shelf. If I decide to do some additional upgrades in the future (a/c, electric fan, etc.) I'll swap out this 1G for a 3G. For now, I'd just like to see if I can learn how to successfully modify from the generator to the 1G alternator.

 

[alwill923]

The 10si and 12si alternators are not 1 wire alternators. They are remote sensing. Much better. Go to mad electrical website for more info

Catalog

 

[63 Sprint]

Thanks alwill923. I was thinking of going to a one-wire alternator set-up but had this alternator and regulator from a 1966 Mustang on the shelf. If I decide to do some additional upgrades in the future (a/c, electric fan, etc.) I'll swap out this 1G for a 3G. For now, I'd just like to see if I can learn how to successfully modify from the generator to the 1G alternator.

A 3G upgrade is well worth the investment. They are able to handle the requirements on vehicles with today’s electronics because they put out more amperage and are better in regulating than the 1G alternator. The 3G also has an internal cooling fan which seems to do a better job cooling. A cooler alternator will do a better job charging and regulating. And they normally last longer.

 

[63 Sprint]

Here is a good article from HOTROD:

How-to Install a High-Output Ford 3G Alternator into Older Fords

A Ford 3G integrally regulated alternator is the best choice for replacing old 1G externally regulated alternators on amped-up muscle cars.

www.hotrod.com

 

[bmbm40]

Here is a good article from HOTROD:

How-to Install a High-Output Ford 3G Alternator into Older Fords

A Ford 3G integrally regulated alternator is the best choice for replacing old 1G externally regulated alternators on amped-up muscle cars.

www.hotrod.com

Great article thanks! The 3G is on my list of upgrades and this is a detailed description of how to get it done.

 

[awasson]

Great article thanks! The 3G is on my list of upgrades and this is a detailed description of how to get it done.

Yes, that’s a very comprehensive article. Thanks @63 Sprint

Surprisingly, so far my stock alternator has had no issue supporting the electrical, including halogens, an electric fan + the normal heater fan, wipers, brake lamps and markers. I thought there would be trouble because even before I added halogens, the factory headlamps would cycle off and on while I was driving. That turned out to be weak circuit breakers in the factory headlamp switch (replaced) and I run my halogens off relays, so there is very little load on the switch now. Nevertheless, I’m planning to upgrade to a Ford 3G alternator like the one described for the sake of simplicity and durability.

One of the things I’ve read about the upgrade that we need to keep in mind is that if you have an ammeter gauge, you need to either have it converted to a voltmeter or get a voltmeter to replace it.

 

[bmbm40]

Yes, that’s a very comprehensive article. Thanks @63 Sprint

Surprisingly, so far my stock alternator has had no issue supporting the electrical, including halogens, an electric fan + the normal heater fan, wipers, brake lamps and markers. I thought there would be trouble because even before I added halogens, the factory headlamps would cycle off and on while I was driving. That turned out to be weak circuit breakers in the factory headlamp switch (replaced) and I run my halogens off relays, so there is very little load on the switch now. Nevertheless, I’m planning to upgrade to a Ford 3G alternator like the one described for the sake of simplicity and durability.

One of the things I’ve read about the upgrade that we need to keep in mind is that if you have an ammeter gauge, you need to either have it converted to a voltmeter or get a voltmeter to replace it.

Yep relays are the way to go and I will be incorporating several in my electric upgrade phase for halogens, heater fan, audio amp, radiator cooling fan and whatever else needs it.

At least for early Broncos we have this convenient voltmeter option:

Voltage Gauge | Fits Stock Cluster | 66-77 Bronco, 61-66 Ford Truck

Upgrade your 66-77 Bronco or 61-66 Ford Truck to a voltage gauge for accurate, safe monitoring of its electrical system - fits OE cluster for easy installation.

www.wildhorses4x4.com

 

[65MustangI6]

Thanks everyone for the input. I haven't had the opportunity to review the articles yet but plan to do so today and tomorrow. It sounds like the collective wisdom of the group is to move to the 10 or possibly 12si alternator, so it would be foolish of me with my limited knowledge of alternators to not consider this alternative.

A couple of questions. I've already spent a few bucks to purchase the alternator brackets (moving from generator to alternator) and wiring harness from Falcon Parts. If I move to the Delco 10 or 12si (which was primarily built for GM) do I need to modify the brackets again? What about the fan belt? (I don't have any accessories so the belt only wraps the alternator, fan pulley and crankshaft pulley.) I'm guessing a new harness would also need to be purchased since the new alternator would be internally regulated.

I mentioned earlier I wasn't planning to add a lot of electrical extras, at least at the moment (other than I do plan to upgrade to electronic ignition by adding the Pertronix II in the near future). That's why my plan was to use the 1G alternator and the request to confirm the wiring set-up on my hand drawn wiring diagram. The wiring modification seemed to be straight forward but it's always good to have a second set of eyes, or in this case, many sets of eyes.

Thanks again for the input . . . now on to reading/studying the articles.

 

[Otto]

My '64 Econoline came to me with its original 35 amp generator and external voltage regulator. I removed the gen & voltage reg and installed a Delco 10SI that puts out 63 amps. Plenty for my use.

I did have a 1G Ford alternator that was already on the 200 that got swapped into the van, but went with the 10SI because it weighed 1/2 of the Ford alt. It also took far less effort to turn it. Another big thing for me is a 10SI is the most common alternator on earth and even the smallest auto parts store in the most remote part of the country will likely have one on the shelf.

You'll probably have to adjust the mounting for the 10SI, but as I remember it wasn't a lot to deal with. Wiring it is simple too if you're leaning this direction.

 

[bmbm40]

Thanks everyone for the input. I haven't had the opportunity to review the articles yet but plan to do so today and tomorrow. It sounds like the collective wisdom of the group is to move to the 10 or possibly 12si alternator, so it would be foolish of me with my limited knowledge of alternators to not consider this alternative.

A couple of questions. I've already spent a few bucks to purchase the alternator brackets (moving from generator to alternator) and wiring harness from Falcon Parts. If I move to the Delco 10 or 12si (which was primarily built for GM) do I need to modify the brackets again? What about the fan belt? (I don't have any accessories so the belt only wraps the alternator, fan pulley and crankshaft pulley.) I'm guessing a new harness would also need to be purchased since the new alternator would be internally regulated.

I mentioned earlier I wasn't planning to add a lot of electrical extras, at least at the moment (other than I do plan to upgrade to electronic ignition by adding the Pertronix II in the near future). That's why my plan was to use the 1G alternator and the request to confirm the wiring set-up on my hand drawn wiring diagram. The wiring modification seemed to be straight forward but it's always good to have a second set of eyes, or in this case, many sets of eyes.

Thanks again for the input . . . now on to reading/studying the articles.

Sounds like a good upgrade to your Mustang as the old generators did not put out much power from my understanding. If you don't mind a suggestion for ignition the DSII is well regarded on this forum and mine has worked well.

 

[alwill923]

I just modified the generator bracket to fit the 10si. i did have to drill out the ear on the 10si to accept the the mounting bolt. May be better way to do it, but that was the easiest way for me at the time.

 

[63 Sprint]

alwill923,
A 10si should work ok. It’s not my first choice but it’s better than some other alternatives. Since you decided on going with 10si, why don’t you go for a 12si? It has the same dimensions, has an higher rating and has an upgraded cooling fan.

This short paragraph is addressed for others, not alwill923. Alwill923 already understands what I’m about to write. I would recommend using the three wire 10si or 12si hookups. The next sentence is my personal opinion. Stay away from the aftermarket 10si and 12si single wire hookups.

In the future, if anyone has problems with the 10si or 12si overheating, switching to the 3G is always an option.

 

[drag-200stang]

They sell for less than 10 dollars small digital volt gauges that fit in a 1.125 hole flush with a nut that tightens down from in back. It would be nice to know what the charge state of battery and charging voltage. Forget that idiot warning light.
Search ''digital DC 12-24 volt gauge''. I am going to get one for lawn tractor/ snow blower. Hot rod voltage will be displayed on digital dash, no need for one there.

 

[65MustangI6]

Sounds like a good upgrade to your Mustang as the old generators did not put out much power from my understanding. If you don't mind a suggestion for ignition the DSII is well regarded on this forum and mine has worked well.

Thanks for the feedback. I'll certainly take a look at the DSII when I start to look at changing to electronic ignition.

 

[65MustangI6]

alwill923,
A 10si should work ok. It’s not my first choice but it’s better than some other alternatives. Since you decided on going with 10si, why don’t you go for a 12si? It has the same dimensions, has an higher rating and has an upgraded cooling fan.

This short paragraph is addressed for others, not alwill923. Alwill923 already understands what I’m about to write. I would recommend using the three wire 10si or 12si hookups. The next sentence is my personal opinion. Stay away from the aftermarket 10si and 12si single wire hookups.

In the future, if anyone has problems with the 10si or 12si overheating, switching to the 3G is always an option.

I haven't made any decisions yet, other than my original plan of installing the 1G alternator from a '66 Mustang that I had available. I've now read both articles and certainly thinking about the Ford 3G discussed in the Hot Rod article. I need to study both articles as well as do some of my own research to find out the best options and then what is required to modify both the brackets and wiring. Being a novice with alternators it certainly seems like there are tons of choices and each choice impacts something else. Fun times . . .