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-   -   Gen to Alt Conversion - Easy? (https://www.fordbarn.com/forum/showthread.php?t=325544)

Stephenorf 04-14-2023 01:09 PM

Gen to Alt Conversion - Easy?
 

I think I want to convert the 312 in my 1959 Merc to an alternator setup. Other than mounting and aligning the alt to replace the gen, are there any other concerns I need to be aware of? I'm thinking it can't be as easy as a plug-and-play swithover...or can it?

Thanks in advance,
Stephen

miker98038 04-14-2023 01:21 PM

Re: Gen to Alt Conversion - Easy?
 

If it’s a 12 volt car already it’s pretty straight forward. But which alternator you choose will affect that. If it’s an internal regulator (3 or 1 wire) you’ll need to deal with that. If it’s a separate regulator, same thing. If you’re going way up in amperage output to run heavy electrical loads, the output wire all the way to the battery terminal will need to be appropriately sized. And you need to figure out how to get the “red light” to work too.

I’m not a big fan of 1 wires adapted to a different vehicle. I’ve seen lower voltage at the battery then I like on some. Depends on the wire length and gauge between the alternator and the battery.

But in most cases you don’t get into all of those items. Just something to be aware off.

Ole Don 04-14-2023 01:21 PM

Re: Gen to Alt Conversion - Easy?
 

On that car, it may be that easy. It is already twelve volt - ground, just make sure the hot from the alternator is in good shape and able to handle the load without heating up.

Stephenorf 04-14-2023 02:10 PM

Re: Gen to Alt Conversion - Easy?
 

2 Attachment(s)
Quote:

Originally Posted by miker98038 (Post 2218759)
If it’s a 12 volt car already it’s pretty straight forward. But which alternator you choose will affect that. If it’s an internal regulator (3 or 1 wire) you’ll need to deal with that. If it’s a separate regulator, same thing. If you’re going way up in amperage output to run heavy electrical loads, the output wire all the way to the battery terminal will need to be appropriately sized. And you need to figure out how to get the “red light” to work too.

I’m not a big fan of 1 wires adapted to a different vehicle. I’ve seen lower voltage at the battery then I like on some. Depends on the wire length and gauge between the alternator and the battery.

But in most cases you don’t get into all of those items. Just something to be aware off.

Hi, I was thinking of using an alternator from a 1965/1966 Mustang (289ci/302ci). It is a "standard" 3-wire hookup with an external voltage regulator. I think the ones I have laying around are all 55 amp alternators.

https://www.fordbarn.com/forum/attac...1&d=1681499303

1966 Autolite alternator for a V8, 55A 15V External VR - I have a few and they all tested good at the local Autozone.

https://www.fordbarn.com/forum/attac...1&d=1681499303

Stephenorf 04-14-2023 02:27 PM

Re: Gen to Alt Conversion - Easy?
 

2 Attachment(s)
Quote:

Originally Posted by Ole Don (Post 2218760)
On that car, it may be that easy. It is already twelve volt - ground, just make sure the hot from the alternator is in good shape and able to handle the load without heating up.

Yes, that's right....it is a 12v negative ground already. I'm wondering if I'll neeed to swap voltage regulators when I move from DC to AC?

Here's the type of DC VR that currently is working with the Gen setup....
https://www.fordbarn.com/forum/attac...1&d=1681500272

And the type of VR that normally goes with the early Mustang 55A Alternator...
https://www.fordbarn.com/forum/attac...1&d=1681500272

miker98038 04-14-2023 03:21 PM

Re: Gen to Alt Conversion - Easy?
 

I’m sure you’ll need to swap the regulator. Probably also marginal on the output wire, but that’s a guess. I don’t know the generator output. Typical #10 (10 gauge, American wire gauge standards) is 30 amp. It depends to some degree on the insulation ratings. But at least take a look what Ford used with those on the Mustangs.

Gene F 04-15-2023 04:21 PM

Re: Gen to Alt Conversion - Easy?
 

I have a 12V 1957 Skyliner, and have always wondered the same things Stephenorf. I am afraid of not getting straight answers, so I am leaving mine alone. One day I will meet up with one of the guys that has done this at a cruise-in that will answer my questions, and let me look at his/her car. I just hate finding things out the hard way as I age.

Stephenorf 04-15-2023 04:52 PM

Re: Gen to Alt Conversion - Easy?
 

Quote:

Originally Posted by Gene F (Post 2219036)
I have a 12V 1957 Skyliner, and have always wondered the same things Stephenorf. I am afraid of not getting straight answers, so I am leaving mine alone. One day I will meet up with one of the guys that has done this at a cruise-in that will answer my questions, and let me look at his/her car. I just hate finding things out the hard way as I age.

Hi Gene, I agree. I'm not sure about the "quirks" of these old cars when going from 12V DC to 12V AC. Seems like it could be straight forward...but I'm often not suprised when things are not as expected. I was hoping someone here was familiar with the conversion process and could let me know what to watch out for/expect.

Gene F 04-15-2023 08:33 PM

Re: Gen to Alt Conversion - Easy?
 

Yes, things like the pigtail on the voltage regulator..... what regulator fits that pigtail? How do you get the GEN light to work after the conversion. stuff like thta that no one seems ot wanna answer. Most small time vendors/mfrs don't want to answer these questions, and when you look at their instuctions they often simply tell you how to bolt on the part. I need more than that!!!!!!!

fordor41 04-15-2023 10:15 PM

Re: Gen to Alt Conversion - Easy?
 

Quote:

Originally Posted by miker98038 (Post 2218759)
If it’s a 12 volt car already it’s pretty straight forward. But which alternator you choose will affect that. If it’s an internal regulator (3 or 1 wire) you’ll need to deal with that. If it’s a separate regulator, same thing. If you’re going way up in amperage output to run heavy electrical loads, the output wire all the way to the battery terminal will need to be appropriately sized. And you need to figure out how to get the “red light” to work too.

I’m not a big fan of 1 wires adapted to a different vehicle. I’ve seen lower voltage at the battery then I like on some. Depends on the wire length and gauge between the alternator and the battery.

But in most cases you don’t get into all of those items. Just something to be aware off.


We installed a GM alt on our '41 Ford with a 302. Local shop rewired for 1 wire. worked great. Have a '60 Ford 292 now with 1 wire alt. and it also works good. No messing with Voltage regs. 1 wire to the + on battery and good to go. If you can't find large enough wire to suit your needs run 2 wires together..

Stephenorf 04-16-2023 07:52 AM

Re: Gen to Alt Conversion - Easy?
 

I found this on another forum:

Seems the conversion in the link below is for an early Galaxy, but I would expect the details to be very similar to any early Ford. The article also apparenty addresses the GEN/ALT light issue.

http://www.galaxieclub.com/alternator-conversion.html

5851a 04-16-2023 09:07 AM

Re: Gen to Alt Conversion - Easy?
 

I used the complete Alt charging set up from a 65 Galaxie on a 56 Ford. The Alt, the wiring to the regulator and gutted the cars harness to get the resistance wire and charge bulb. The resistance wire just parallels the red light wire so if the bulb burns out it will keep charging. Worked great. The 65 was selected since it was the 352 donor for the 56 and had all the parts needed. If you do go the salvage route select a donor car with the red lamp and not the gauges as the harnesses are different. You will need to strip the entire harness to follow the lamp wire back to the ignition switch. There are easier methods but it was no cost for me at the time.

KULTULZ 04-16-2023 09:12 AM

Re: Gen to Alt Conversion - Easy?
 

1 Attachment(s)
I'm a PURIST, OK?

I don't speak DELCO, POWERMASTER, INTERSTATE or STANT. It is either FORD or it ain't.

Here is info on an OEM appearance install.

Carefully pick though unless you wear a BOW-TIE.

http://forums.y-blocksforever.com/Topic115656-1.aspx

No food fights please ...

- EDIT - FORGOT TO MENTION -

I once had a photo of a 1G CONV and the guy had painted the ALT BLACK and put a GEN DECAL on it. From the top view, it was hard to distinguish the conversion.


KULTULZ 04-16-2023 10:52 AM

Re: Gen to Alt Conversion - Easy?
 

Quote:

I was thinking of using an alternator from a 1965/1966 Mustang (289ci/302ci). It is a "standard" 3-wire hookup with an external voltage regulator. I think the ones I have laying around are all 55 amp alternators.
If you look @ the mounting boss, the ALT ID and AMP should be stamped there, unless it has been through a re-builder. You can (could) buy a kit to pump it up to 100A if needed.

rotorwrench 04-16-2023 11:45 AM

Re: Gen to Alt Conversion - Easy?
 

The alternators all have the internal diode bridge to prevent reverse current draw. The electro-mechanical voltage regulators were two pole types but have to match the current output of the alternator. They have a preset current limiter pole and a voltage regulator pole. The cut out relay that the early generator voltage controlers had (three pole units) is not needed on an alternator. Most generators were no more than 35 amp for the average automobile. The alternators are generally over 40 amps in output.

A person can use any one wire alternator since may can be set up to excite through a warning light. It just takes using the two unused wire connections. This one is for a GM 10si.
http://www.expeditionlandrover.info/...ternators.html

Charlie Stephens 04-16-2023 12:12 PM

Re: Gen to Alt Conversion - Easy?
 

Just curious, why do you want to change? Unless you have something that needs a lot of power I would keep the generator. Find a good shop to completely rebuild it and it should last 100K miles.

Charlie Stephens

Stephenorf 04-16-2023 12:28 PM

Re: Gen to Alt Conversion - Easy?
 

Quote:

Originally Posted by Charlie Stephens (Post 2219214)
Just curious, why do you want to change? Unless you have something that needs a lot of power I would keep the generator. Find a good shop to completely rebuild it and it should last 100K miles.

Charlie Stephens

The reason I'm thinking about changing to alternator is because they are off-the-shelf available (plus I have a bunch of good used ones just laying around), and because on low RPM the gen seems to not put out enough power. Also, this is my first generator-powered car and I'm not as familiar with the generators. Lastly, I see a lot of older cars that have been "converted" to alternator, so I'm assuming there must be an intrinsic value to swapping to alt vs staying with the factory gen.

dmsfrr 04-16-2023 02:00 PM

Re: Gen to Alt Conversion - Easy?
 

Quote:

Originally Posted by Stephenorf (Post 2219224)
. . . Lastly, I see a lot of older cars that have been "converted" to alternator, so I'm assuming there must be an intrinsic value to swapping to alt vs staying with the factory gen.

One practical reason...
When air conditioning and extra cooling fans are added more electrical power is usually needed.

Gene F 04-16-2023 03:14 PM

Re: Gen to Alt Conversion - Easy?
 

Try a retractable. Lot of current draw as that thing is heavier than you would think. Plus a car with a gen can often times see very faint pulses in the headlights at idle. I would like to convert my ignition to electronic, and I think the gen set up would be a bit hard on it. No oiling the bearing every season with an alternator.

5851a 04-16-2023 03:47 PM

Re: Gen to Alt Conversion - Easy?
 

Personally I would just stick with the known Ford parts. When you start going with the 1 wire things and something fails in a 1 horse town you can find a Ford 1G without too much trouble. You start asking for a self exciting regulator equipped 1 wire Case backhoe with a Delco alt you may be in for a wait. OT but case in point, heading out for 3600 mile trip, heard a loud squeal under hood, stepped on clutch and engine killed. G1 bearing seized. Coasted to a driveway, owner came out and asked if he could help. Asked if he had a Ford alt, he did since his brother in law had left his car there and he didn't ever care for him. Think it was from a 71 country sedan, that was in 81 and it's still on my 67. The price at the time was a 6 pack. Just stick with the Ford parts, JMO.

KULTULZ 04-16-2023 05:54 PM

Re: Gen to Alt Conversion - Easy?
 

Quote:

The price at the time was a 6 pack.

I've been known to do repairs for beer ... :p

Stephenorf 04-16-2023 06:12 PM

Re: Gen to Alt Conversion - Easy?
 

Quote:

Originally Posted by dmsfrr (Post 2219258)
One practical reason...
When air conditioning and extra cooling fans are added more electrical power is usually needed.

That's a good point. In my 59, the previous owner had installed an air conditioning unit. It's not working yet, but the compressor is hooked up under the hood and the hang on under the dash condensers right there. I'm hoping all I have to do is charge it with freon to get it going. Anyhow, if an alternator is a better option, then there's a good reason for swapping the gen for an alternator.

rotorwrench 04-16-2023 06:34 PM

Re: Gen to Alt Conversion - Easy?
 

I prefer to use all three wires myself. The one wire will self energize but it takes a bit more rpm than idle speed. The GEN light connection turns it on immediately.

Stephenorf 04-16-2023 07:11 PM

Re: Gen to Alt Conversion - Easy?
 

Quote:

Originally Posted by Gene F (Post 2219279)
Try a retractable. Lot of current draw as that thing is heavier than you would think. Plus a car with a gen can often times see very faint pulses in the headlights at idle. I would like to convert my ignition to electronic, and I think the gen set up would be a bit hard on it. No oiling the bearing every season with an alternator.

Does the factory generator require specific maintenance? :eek: Like manually oiling a bearing?

Stephenorf 04-16-2023 07:15 PM

Re: Gen to Alt Conversion - Easy?
 

Quote:

Originally Posted by 5851a (Post 2219292)
Personally I would just stick with the known Ford parts. When you start going with the 1 wire things and something fails in a 1 horse town you can find a Ford 1G without too much trouble. You start asking for a self exciting regulator equipped 1 wire Case backhoe with a Delco alt you may be in for a wait. OT but case in point, heading out for 3600 mile trip, heard a loud squeal under hood, stepped on clutch and engine killed. G1 bearing seized. Coasted to a driveway, owner came out and asked if he could help. Asked if he had a Ford alt, he did since his brother in law had left his car there and he didn't ever care for him. Think it was from a 71 country sedan, that was in 81 and it's still on my 67. The price at the time was a 6 pack. Just stick with the Ford parts, JMO.

Cool story. So I was planning on goin with a '1965/1966' Mustang alternator. It is like 55 amps, and uses a standard external regulator. I'm not sure about going to a GM-style 1-wire setup. This particular alternator is pretty mucha available in any auto parts store as there are so many applications for the alternator.

fordor41 04-16-2023 10:29 PM

Re: Gen to Alt Conversion - Easy?
 

Quote:

Originally Posted by rotorwrench (Post 2219353)
I prefer to use all three wires myself. The one wire will self energize but it takes a bit more rpm than idle speed. The GEN light connection turns it on immediately.

When I installed a single wire alt (GM) my local rebuilder upgraded our alt so it charged at idle instead of 12-1500 RPM.

rotorwrench 04-18-2023 01:39 PM

Re: Gen to Alt Conversion - Easy?
 

The folks that maintain their old generator systems have also been using reproduction voltage controllers when needed. They're not made near as well as the old originals. I would fear that the 12-volt alternator controllers that are currently produced may suffer the same problems. If a person has a problem with an internal solid state regulator then the problem can be pinpointed to the alternator itself in most cases. The parts to overhaul a 10si are still reasonable in price and so far they are relatively reliable. I've been using a 10si on my Ford 850 tractor for many years. I have one on my model A as well but it's a 6-volt conversion.

Generators work well and the old controllers last very well but they will need an overhaul after years of service. It's when a person installs a bunch of high amp accessories like air conditioning and such, that the alternator makes more sense.

Gene F 04-18-2023 07:26 PM

Re: Gen to Alt Conversion - Easy?
 

There is a little oil cap on the gen for the bearing area. 1 x per yr usually does it. a drop or two.

Stephenorf 04-19-2023 02:23 PM

Re: Gen to Alt Conversion - Easy?
 

Quote:

Originally Posted by Gene F (Post 2219929)
There is a little oil cap on the gen for the bearing area. 1 x per yr usually does it. a drop or two.

Thanks. Just use regular motor oil? I'll have to look for that oil cap.


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