The Ford Barn

Ramblin Reck · 07-29-2022, 11:55 AM

Can it be positively identified?

Is it a Generator or an Alternator on my 1939 Ford] Convertible with a replaced flat head engine. The engine is a 1947 or '48, 100HP, 59A-B, replacement with 12Volt, Positive Ground. There are no markings on it or evidence of tags removed. Previous owner has gone on to the Big Junkyard in the Sky with the sign that says "Take what you need!"

Thanks y'all!

deuce lover · 07-29-2022, 12:52 PM

Looks like a generator.Is there a voltage regulator on the firewall?

jayvee34 · 07-29-2022, 02:11 PM

Based on the middle photo, it looks like a generator due to the length of it.
The "power gen" (generator/alternator look alike) is shorter and somewhat fatter.

If you have a voltage regulator on the fire wall, would just about confirm it to be
a generator.

Ramblin Reck · 07-29-2022, 02:52 PM

Quote:

Originally Posted by deuce lover

Looks like a generator.Is there a voltage regulator on the firewall?

Yes sir, there is a 12v Regulator on the wall.

Ramblin Reck · 07-29-2022, 02:59 PM

Quote:

Originally Posted by jayvee34

Based on the middle photo, it looks like a generator due to the length of it.
The "power gen" (generator/alternator look alike) is shorter and somewhat fatter.

If you have a voltage regulator on the fire wall, would just about confirm it to be
a generator.

Roger that Jayvee, a 12v Regulator is on the firewall. I measured the length and it is 8.5" from the back to the end of the pulley. Hope this finds you well my friend!

cas3 · 07-29-2022, 10:25 PM

Sponsored Links (Register now to hide all advertisements)

It would be odd to go 12 volt and stay positive ground. Usually the reason to go 12 volt would be to run modern accessory's, but that would require negative ground also. I would be tempted to have a look inside

cadillac512 · 07-29-2022, 10:48 PM

Simple test: An alternator will have power all the time to the output post. A generator will only have power there with the car running.

Terry

Ramblin Reck · 07-30-2022, 07:19 AM

Quote:

Originally Posted by cas3

It would be odd to go 12 volt and stay positive ground. Usually the reason to go 12 volt would be to run modern accessory's, but that would require negative ground also. I would be tempted to have a look inside

No doubt about it, that it is Positive Ground. Follow the Red Wire from the post to the firewall. Follow the Black Negative wire to the Solenoid. What are you suggesting that I "should look into?"

terry · 07-30-2022, 08:47 AM

Don't fix what ain't broken. I went with 12v positive ground for for quite a few years on my 36 Ford. terry

Ramblin Reck · 07-30-2022, 09:06 AM

Quote:

Originally Posted by cadillac512

Simple test: An alternator will have power all the time to the output post. A generator will only have power there with the car running.

Terry

Are you referring to one of the two posts shown in this pic on the round black thing which may be a Generator or maybe an Alternator or are you referring to the battery posts?

Ramblin Reck · 07-30-2022, 09:09 AM

Quote:

Originally Posted by terry

Don't fix what ain't broken. I went with 12v positive ground for for quite a few years on my 36 Ford. terry

Terry
Thanks I agree with you 110%!

cadillac512 · 07-30-2022, 11:17 AM

Quote:

Originally Posted by Ramblin Reck

Are you referring to one of the two posts shown in this pic on the round black thing which may be a Generator or maybe an Alternator or are you referring to the battery posts?

The posts in your pic....but never mind. I can see the commutator and part of a brush through the opening in the housing. It's a generator for sure!

Terry

Newc · 07-30-2022, 08:15 PM

An alternator will bump your car to Touring A Class with all the hotrods for V8 Judging. Newc

cas3 · 07-30-2022, 09:54 PM

Not my Whitney conversion, you wouldn't know it was there unless I told you

Tinker · 07-31-2022, 01:13 AM

Depends on what you want or going for.

Ramblin Reck · 07-31-2022, 07:18 AM

Quote:

Originally Posted by cadillac512

The posts in your pic....but never mind. I can see the commutator and part of a brush through the opening in the housing. It's a generator for sure!

Terry

Terry
Thanks I feel much more confident calling it a Generator now

jayvee34 · 07-31-2022, 03:02 PM

Quote:

Originally Posted by Ramblin Reck

Roger that Jayvee, a 12v Regulator is on the firewall. I measured the length and it is 8.5" from the back to the end of the pulley. Hope this finds you well my friend!

Thanks for asking. Doing very well my friend.

dakotafarmboy · 07-31-2022, 08:38 PM

Cadillac….I loved the quote from Smokey Yunick. He has to be my favorite stock car celebrity! He could go a ways further on a tank of gas than anybody else one Sunday and he got inspected after the race. He was running a 2 inch fuel line!! Smokey correctly pointed out that his tank was within specs. NASCAR put a rule in the next day that limited the size of the fuel line…

07-29-2022, 12:52 PM	#2
deuce lover Senior Member Join Date: May 2010 Location: Southern France Posts: 5,332	Re: Generator or Alternator, that is the question. Looks like a generator.Is there a voltage regulator on the firewall?

07-29-2022, 02:11 PM	#3
jayvee34 Senior Member Join Date: Apr 2021 Location: St. Augustine, Fl. Posts: 438	Re: Generator or Alternator, that is the question. Based on the middle photo, it looks like a generator due to the length of it. The "power gen" (generator/alternator look alike) is shorter and somewhat fatter. If you have a voltage regulator on the fire wall, would just about confirm it to be a generator. __________________ IN GOD WE TRUST - SEMPER FIDELIS John

07-29-2022, 10:25 PM	#6
cas3 Senior Member Join Date: Jan 2011 Location: sw minnesota Posts: 4,609	Re: Generator or Alternator, that is the question. Sponsored Links (Register now to hide all advertisements) It would be odd to go 12 volt and stay positive ground. Usually the reason to go 12 volt would be to run modern accessory's, but that would require negative ground also. I would be tempted to have a look inside

07-29-2022, 10:48 PM	#7
cadillac512 Senior Member Join Date: Apr 2019 Location: Kansas Posts: 993	Re: Generator or Alternator, that is the question. Simple test: An alternator will have power all the time to the output post. A generator will only have power there with the car running. Terry __________________ "It don't take but country smarts to solve the problem" (Smokey Yunick) '41 Merc Town Sedan / 260" 8CM engine '66 Fairlane four door / "warmed up" 302

07-30-2022, 08:47 AM	#9
terry Senior Member Join Date: May 2010 Posts: 275	Re: Generator or Alternator, that is the question. Don't fix what ain't broken. I went with 12v positive ground for for quite a few years on my 36 Ford. terry

07-30-2022, 08:15 PM	#13
Newc Senior Member Join Date: May 2010 Posts: 2,527	Re: Generator or Alternator, that is the question. An alternator will bump your car to Touring A Class with all the hotrods for V8 Judging. Newc

07-30-2022, 09:54 PM	#14
cas3 Senior Member Join Date: Jan 2011 Location: sw minnesota Posts: 4,609	Re: Generator or Alternator, that is the question. Not my Whitney conversion, you wouldn't know it was there unless I told you

07-31-2022, 01:13 AM	#15
Tinker Senior Member Join Date: May 2010 Location: MN Posts: 7,063	Re: Generator or Alternator, that is the question. Depends on what you want or going for.

07-31-2022, 08:38 PM	#18
dakotafarmboy Member Join Date: Apr 2018 Location: South Dakota Posts: 40	Re: Generator or Alternator, that is the question. Cadillac….I loved the quote from Smokey Yunick. He has to be my favorite stock car celebrity! He could go a ways further on a tank of gas than anybody else one Sunday and he got inspected after the race. He was running a 2 inch fuel line!! Smokey correctly pointed out that his tank was within specs. NASCAR put a rule in the next day that limited the size of the fuel line…