641 6 volt coil question

[ole fred]

I'm in the process of converting my 641 to 12 volt after my 6 volt battery went kapoot.

I took the coil off to just clean all the oil and dirt off of it and found that the two low volt connectors are labeled Dist. & Bat. I have never had much reason to pay attention to the coils on my stuff for the last 60+ years, but the one's I have looked at were marked + & - .

With that in mind, I'm betting this coil is the original for the tractor as Ford was 6 volt positive ground until 1955 on cars and later on tractors. Does this mean that the coil was made for 6 volt positive ground stuff? I'm betting so.

What do you think?

Oh yeah, I'm switching the connectors as the system will be negative ground at 12 volts.

 

[Duner Wi]

What do you think?
I think you can determine if your coil is wired correctly with a number 2 lead pencil.

 

[Tony Jacobs]

I'm in the process of converting my 641 to 12 volt after my 6 volt battery went kapoot.

I took the coil off to just clean all the oil and dirt off of it and found that the two low volt connectors are labeled Dist. & Bat. I have never had much reason to pay attention to the coils on my stuff for the last 60+ years, but the one's I have looked at were marked + & - .

With that in mind, I'm betting this coil is the original for the tractor as Ford was 6 volt positive ground until 1955 on cars and later on tractors. Does this mean that the coil was made for 6 volt positive ground stuff? I'm betting so.

What do you think?

Oh yeah, I'm switching the connectors as the system will be negative ground at 12 volts.

Hello Fred , Yes that is an original Ford 6 Volt only coil . Napa made them that way also years ago . It would not surprise in the least that one has survived all these years . I am sure I have a couple of them kicking around shop in one of my cabinets .

 

[soaked]

Hi guys,
Original coil is 8ba 12029. Side mount 8n from 1950 up through 4 cylinder thousand series in 64?

But the best part of an original style 6 volt coil, is the Dimple----
It fits in the hole on the coil bracket, maintaining proper height/position.

 

[ole fred]

What do you think?
I think you can determine if your coil is wired correctly with a number 2 lead pencil.

I hear ya, but I was more interested in the way it was marked. If this coil was put on a '53 Chevy, and hooked up the way it was marked, it wouldn't be correct as Chevy was negative ground. I wonder if NAPA would sell you a different coil in 1953 for a Chevy than a Ford. I was to young in 1953 to know the difference, but I did own one.

 

[Tony Jacobs]

I hear ya, but I was more interested in the way it was marked. If this coil was put on a '53 Chevy, and hooked up the way it was marked, it wouldn't be correct as Chevy was negative ground. I wonder if NAPA would sell you a different coil in 1953 for a Chevy than a Ford. I was to young in 1953 to know the difference, but I did own one.

All 6 Volt is positive ground regardless of make . I am a Chevy guy also and have been for 50 years .

 

[Tony Jacobs]

Hi guys,
Original coil is 8ba 12029. Side mount 8n from 1950 up through 4 cylinder thousand series in 64?
View attachment 158411
But the best part of an original style 6 volt coil, is the Dimple----
It fits in the hole on the coil bracket, maintaining proper height/position. View attachment 158412

This is true ! Not very common any more but still around . 1965 was the last year for 4 cylinder Fords right up until December 31st .

 

[ole fred]

All 6 Volt is positive ground regardless of make . I am a Chevy guy also and have been for 50 years .

Huh? Model T Fords were negative ground - after they got electric starters. Ford switched to positive ground with the Model A's. I have a 29 Chevy that is negative ground. I'm pretty sure that GM was always negative ground.

 

[Duner Wi]

All 6 Volt is positive ground regardless of make . I am a Chevy guy also and have been for 50 years .

Not all 6 volt is positive ground. Some GM was positive but not any 6 volt Chevy's from the factory.

 

[Tony Jacobs]

Huh? Model T Fords were negative ground - after they got electric starters. Ford switched to positive ground with the Model A's. I have a 29 Chevy that is negative ground. I'm pretty sure that GM was always negative ground.

Never seen a negative ground 6 volt battery in my life . Just as there is no such thing as a 12 volt postive ground battery although Packard did use a 12 volt positive ground system for a few years just before they closed up shop forever . Batteries are assembled from positive and negative plates in the order of flow through the battery from power to ground regardless of which way or voltage . I learned that GM Electrical Engineering school years ago don’t see any evidence that it has changed today . Chevy didn’t go to negative ground until 1955 when the 265 V8 was introduced . My 1937 Chevy 11/2 ton Dump was 6 volt positive ground when it still had the 216 in it . When I updated it with a 1962 261 that had a 12 volt generator on it I updated the truck to 12 volt negative ground . Now I know there is a lot of morons out that will drain a battery completely dead and recharge them with the polarity reversed to change the ground and I have seen plenty of them explode because the battery wasnt manufactured in that direction just as I seen plenty of idiots blow batteries because they were not paying attention when connecting jumper cables . I have never received an acid bath and never plan on getting one so I pay very close attention to those particular details .

 

[Tony Jacobs]

Not all 6 volt is positive ground. Some GM was positive but not any 6 volt Chevy's from the factory.View attachment 158427

Well Duner , I have no idea what you have there other a partial page printed by who and about what ? But you just said there is no Chevy 6 volt positive ground either and yet the book contradicts you and the shows negative what ? I have never seen or worked on any GM product with a 6 volt negative ground or never taught that in GM Electrical Engineering school . Other than that I can’t say that much . Maybe it was an odd Marine application ? Maybe the page is a misprint ? I have no idea . I have close to 1000 cars , trucks and pieces of equipment not to mention all the stuff I have repaired and continue to repair . If you have a specific detail of something printed by GM I would love to see it anything else is completely meaningless to me because it should have been taught in the class if GM did in the past . I have stood on the assembly line and watched as batteries were built and the process explained and reversing polarity was a big no no . I can’t speak as to Marine or to Airplane applications or any Military besides 24 and 36 volt systems . I never say never because anything is possible but probable and commonplace are two different things I can only comment on the last 40plus years of what I seen , done and was taught .

 

[Duner Wi]

Well Duner , I have no idea what you have there other a partial page printed by who and about what ? But you just said there is no Chevy 6 volt positive ground either and yet the book contradicts you and the shows negative what ? I have never seen or worked on any GM product with a 6 volt negative ground or never taught that in GM Electrical Engineering school . Other than that I can’t say that much . Maybe it was an odd Marine application ? Maybe the page is a misprint ? I have no idea . I have close to 1000 cars , trucks and pieces of equipment not to mention all the stuff I have repaired and continue to repair . If you have a specific detail of something printed by GM I would love to see it anything else is completely meaningless to me because it should have been taught in the class if GM did in the past . I have stood on the assembly line and watched as batteries were built and the process explained and reversing polarity was a big no no . I can’t speak as to Marine or to Airplane applications or any Military besides 24 and 36 volt systems . I never say never because anything is possible but probable and commonplace are two different things I can only comment on the last 40plus years of what I seen , done and was taught .

Motors Manual for cars. You want to see the whole page.?

 

[Tony Jacobs]

Motors Manual for cars. You want to see the whole page.?

No that’s fine I don’t use motor manuals and I don’t understand why that wasn’t taught in school that’s all maybe GM in the late 70’s deemed that was no longer important in electrical engineering .

 

[Duner Wi]

No that’s fine I don’t use motor manuals and I don’t understand why that wasn’t taught in school that’s all maybe GM in the late 70’s deemed that was no longer important in electrical engineering .

Page from my veteran Neihoff electrical parts catalog.

 

[Jim.ME]

I'm in the process of converting my 641 to 12 volt after my 6 volt battery went kapoot.

I took the coil off to just clean all the oil and dirt off of it and found that the two low volt connectors are labeled Dist. & Bat. I have never had much reason to pay attention to the coils on my stuff for the last 60+ years, but the one's I have looked at were marked + & - .

With that in mind, I'm betting this coil is the original for the tractor as Ford was 6 volt positive ground until 1955 on cars and later on tractors. Does this mean that the coil was made for 6 volt positive ground stuff? I'm betting so.

What do you think?

Oh yeah, I'm switching the connectors as the system will be negative ground at 12 volts.

The when and where debate of original positive or negative grounds aside. If you are converting it to a 12-volt negative ground system, why not install a new 12-volt coil, wired for negative ground, and eliminate the need for a ballast resistor ahead of the coil?

 

[Duner Wi]

Chevy in 55 and IH when they went to 12 volt in gas tractors in mid 50s supplied 12 volt to coil while cranking by bypassing the ballast resistor. This can help in winter and if your battery is weak.

 

[BradCNY]

Never seen a negative ground 6 volt battery in my life . Just as there is no such thing as a 12 volt postive ground battery although Packard did use a 12 volt positive ground system for a few years just before they closed up shop forever . Batteries are assembled from positive and negative plates in the order of flow through the battery from power to ground regardless of which way or voltage . I learned that GM Electrical Engineering school years ago don’t see any evidence that it has changed today . Chevy didn’t go to negative ground until 1955 when the 265 V8 was introduced . My 1937 Chevy 11/2 ton Dump was 6 volt positive ground when it still had the 216 in it . When I updated it with a 1962 261 that had a 12 volt generator on it I updated the truck to 12 volt negative ground . Now I know there is a lot of morons out that will drain a battery completely dead and recharge them with the polarity reversed to change the ground and I have seen plenty of them explode because the battery wasnt manufactured in that direction just as I seen plenty of idiots blow batteries because they were not paying attention when connecting jumper cables . I have never received an acid bath and never plan on getting one so I pay very close attention to those particular details .

I had a 63 vw bug, 6 volt negative ground

 

[Jim.ME]

Chevy in 55 and IH when they went to 12 volt in gas tractors in mid 50s supplied 12 volt to coil while cranking by bypassing the ballast resistor. This can help in winter and if your battery is weak.

To be clear. They supplied a 6-volt coil labeled to use with an external resistor, as the 12-volt coil. The picture of the coil below would be the aftermarket replacement for those coils. Yes, if the resistor bypass wiring was hooked up the coil received battery voltage while the starter was engaged to crank the engine.

ole fred could do this with his old 6-volt coil, as long as he has a resistor ahead of the coil and has a solenoid (relay) with the ignition bypass terminal.

 

[Sean in PA]

This is true ! Not very common any more but still around . 1965 was the last year for 4 cylinder Fords right up until December 31st .

That was the last official model year, but they continued to make small batches of various 4 cylinder models after that. Mostly the 4 cylinder 2000 offset model. They continued making those until the 1710 offset was release because certain customers kept demanding small offset tractors.

 

[Keith Williams]

To be clear. They supplied a 6-volt coil labeled to use with an external resistor, as the 12-volt coil. The picture of the coil below would be the aftermarket replacement for those coils. Yes, if the resistor bypass wiring was hooked up the coil received battery voltage while the starter was engaged to crank the engine.

ole fred could do this with his old 6-volt coil, as long as he has a resistor ahead of the coil and has a solenoid (relay) with the ignition bypass terminal.

View attachment 158487

A 641, heck any ford models before 1965, is not wired to supply 12 volts to a 6 volt coil while the solenoid is active.
Using the solenoid style that can be wired that way will disable the starter interlock safety feature.
Keith