The Ford Barn

Fred A · 09-21-2022, 11:25 AM

I've been going through my pile of generators for my '40. Many are the earlier style, but all have two side terminals. As with so many Ford components, are these aftermarket replacements using a later design? All have Ford part numbers as originals. Was there a trend toward the use of later components by rebuilders. I found two that were stamped 12V and the fields measured different resistance. Apparently, these generators don't get any respect as so many are left as trash after the swap meets. The three brush models are even more commonly abandoned. Why so many two post? Fred A

rotorwrench · 09-21-2022, 07:07 PM

The 81A10000-D style generators were used for those early years of the 2-brush with some 91A and 01A variations. The 21A type changed to the two side terminals for 1942 which was continued in war time and after the war through 1948 on V8s. A lot more of the side post generators were made than the single side post types since they were used so much longer. There is a fair amount of interchangeability with those units so the front mounts will likely fit on either case. They're likely out there but may not be so easy to find.

When rebuilders tore them down, all the cases likely were gutted and cleaned up then put in bins for reuse. It would have been easy to mix and match stuff due to the interchangeability. If they were out of single post cases they likely just used what they had the most of to build them back up. If a person looks at the "part number usage chart" in the chassis parts book, you can see what parts went into each different iteration of these 10000 series 2-brush units. Some parts from the 3-brush generators worked in the 2-brush units so Ford used what ever worked.

Kube · 09-21-2022, 07:14 PM

Quote:

Originally Posted by Fred A

I've been going through my pile of generators for my '40. Many are the earlier style, but all have two side terminals. As with so many Ford components, are these aftermarket replacements using a later design? All have Ford part numbers as originals. Was there a trend toward the use of later components by rebuilders. I found two that were stamped 12V and the fields measured different resistance. Apparently, these generators don't get any respect as so many are left as trash after the swap meets. The three brush models are even more commonly abandoned. Why so many two post? Fred A

Fred, Not certain what you mean by "earlier style but two side terminals". That's a contradiction.
In 1942, two "side" terminals became the design.
The cases are dated so as to make it easy to figure out the proper application.
The front plate changed in 1942.
However, as has been stated in an earlier post, nearly all of the parts interchanged. I doubt very much that a rebuilder cared (nor the consumer) if all "concourse correct" parts were utilized during the rebuilding process.

Respect? I scrapped just shy of 75 of these units last summer. Cores realized nearly $800, by far, much more than anyone was willing to pay me.

Fred A · 09-21-2022, 09:43 PM

By early style, I was referring to the generators with a larger diameter pulley and nut used well into 1940 production. How would I have known that? That the second side terminal use was a '42 change is what I found as conflicting in so many of my cores. I may find that the '40 wiring will not work well with the later side terminals. The plethora configurations of Ford components may be why so many have survived. I will resist picking up the orphans at the swap meets after I get this chassis to make some beautiful noise. The coupe and the A roadster (40B) are my last. Thank You Barners: Fred A

Terry,OH · 09-22-2022, 01:04 PM

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The small third terminal is a ground and is not wired internally, it can be removed. The change to three terminals happened in 1941, it was a good idea since many of the two terminal problems were traced to grounding.

Most of the pre war generator pulleys were cast iron. The 1940 cast iron pulleys have female threads and the armature male. The pulley screws onto the end of the armature and is secured by a retaining clip for safety.

09-21-2022, 11:25 AM	#1
Fred A Senior Member Join Date: May 2010 Location: Encino California, near Burbank Posts: 935	Pre-'42 Two Brush Generators? I've been going through my pile of generators for my '40. Many are the earlier style, but all have two side terminals. As with so many Ford components, are these aftermarket replacements using a later design? All have Ford part numbers as originals. Was there a trend toward the use of later components by rebuilders. I found two that were stamped 12V and the fields measured different resistance. Apparently, these generators don't get any respect as so many are left as trash after the swap meets. The three brush models are even more commonly abandoned. Why so many two post? Fred A

09-21-2022, 07:07 PM	#2
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,440	Re: Pre-'42 Two Brush Generators? The 81A10000-D style generators were used for those early years of the 2-brush with some 91A and 01A variations. The 21A type changed to the two side terminals for 1942 which was continued in war time and after the war through 1948 on V8s. A lot more of the side post generators were made than the single side post types since they were used so much longer. There is a fair amount of interchangeability with those units so the front mounts will likely fit on either case. They're likely out there but may not be so easy to find. When rebuilders tore them down, all the cases likely were gutted and cleaned up then put in bins for reuse. It would have been easy to mix and match stuff due to the interchangeability. If they were out of single post cases they likely just used what they had the most of to build them back up. If a person looks at the "part number usage chart" in the chassis parts book, you can see what parts went into each different iteration of these 10000 series 2-brush units. Some parts from the 3-brush generators worked in the 2-brush units so Ford used what ever worked. Last edited by rotorwrench; 09-21-2022 at 07:16 PM.

09-21-2022, 09:43 PM	#4
Fred A Senior Member Join Date: May 2010 Location: Encino California, near Burbank Posts: 935	Re: Pre-'42 Two Brush Generators? By early style, I was referring to the generators with a larger diameter pulley and nut used well into 1940 production. How would I have known that? That the second side terminal use was a '42 change is what I found as conflicting in so many of my cores. I may find that the '40 wiring will not work well with the later side terminals. The plethora configurations of Ford components may be why so many have survived. I will resist picking up the orphans at the swap meets after I get this chassis to make some beautiful noise. The coupe and the A roadster (40B) are my last. Thank You Barners: Fred A Last edited by Fred A; 11-23-2022 at 11:25 PM.

09-22-2022, 01:04 PM	#5
Terry,OH Senior Member Join Date: May 2010 Posts: 4,751	Re: Pre-'42 Two Brush Generators? Sponsored Links (Register now to hide all advertisements) The small third terminal is a ground and is not wired internally, it can be removed. The change to three terminals happened in 1941, it was a good idea since many of the two terminal problems were traced to grounding. Most of the pre war generator pulleys were cast iron. The 1940 cast iron pulleys have female threads and the armature male. The pulley screws onto the end of the armature and is secured by a retaining clip for safety.