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6v pos ground alternator

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Has anyone converted a GM 10Si 12v alternator to 6v pos ground? My generator checks OK, new battery, new O gauge cables, new V/R, after 10 mins. of driving stops charging. Went back to electrical shop, that said I needed a V/R originally, said they cleaned contacts in new V/R!!!!!!! While driving to a cruise in yesterday, stopped charging after 10 minutes or so, never charged all the way home, 70 mile round trip. 

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Glad you made it home without a flatbed

While there are 6 volt positive ground alts available for $134 last I checked,  Just saying why convert when you can buy for reasonable price?

I had to walk into office to get the link and send it, then back to the shop to finish post   :P

 

 

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Might be stating the obvious here but after ten minutes or so your ammeter should show very low to no charge. Just means the battery is fully up.

 

If that's what's happening your charging system is actually fine.

Any issues restarting, or low battery or anything else to indicate a non functional system?

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5 minutes ago, Los_Control said:

Glad you made it home without a flatbed

While there are 6 volt positive ground alts available for $134 last I checked,  Just saying why convert when you can buy for reasonable price?

I had to walk into office to get the link and send it, then back to the shop to finish post   :P

 

 

Luckily I didn't need headlites!!! The conversion kit is around $40 and an alternator from Rock Auto is $21 and up depending on what you want to spend. I just thought it would be fun to do it myself. Just curious if anyone is using one.

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3 minutes ago, 50mech said:

Might be stating the obvious here but after ten minutes or so your ammeter should show very low to no charge. Just means the battery is fully up.

 

If that's what's happening your charging system is actually fine.

Any issues restarting, or low battery or anything else to indicate a non functional system?

When I put a voltmeter on battery it drops below 6v with loads on. Also while driving home I turned the headlites on, ammeter went more neg., blower motor and defrost motor on went even more neg., so I'm pretty sure it is not charging. I started it today, same thing no charge indicated on ammeter and more loads more negative indication.

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Yep, just making sure.

Sounds like a fun puzzle but if you're switching it out then I guess no need to try haha.

First guess would be cutout relay in the VR needing adjusted.

Edited by 50mech

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2 minutes ago, DJK said:

Luckily I didn't need headlites!!! The conversion kit is around $40 and an alternator from Rock Auto is $21 and up depending on what you want to spend. I just thought it would be fun to do it myself. Just curious if anyone is using one.

I like to learn new things everyday, I have never heard anyone talk about converting a 12 volt alt to 6 volt. I learned something today thanks to you, I did not know when I woke up.

 

Like any troubleshooting, I figure it is best to start at the beginning, remove the VR out of the pic by disconnecting the wires, check the alternator with a multi meter to see is producing a charge. Then next step forward to connect VR and check from there.

 

I have no experience with what you are doing, but I worry about cheap china electrical parts like condensers & points, doa out of the box or work one time and condenser fails.

You drove 10 miles and it stopped working .... get the vr out of the picture and prove the alternator is charging first.

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3 hours ago, DJK said:

Has anyone converted a GM 10Si 12v alternator to 6v pos ground? My generator checks OK, new battery, new O gauge cables, new V/R, after 10 mins. of driving stops charging. Went back to electrical shop, that said I needed a V/R originally, said they cleaned contacts in new V/R!!!!!!! While driving to a cruise in yesterday, stopped charging after 10 minutes or so, never charged all the way home, 70 mile round trip. 

 

In far less time that it would take to figure our how to redo an alternator, this reliable vendor can have an alternator that is ready to bolt to your car at your door in 3-4 days:

 

https://www.ebay.com/str/HowardEnt?_trksid=p2047675.l2563

 

I have had flawless service from the alternator I purchased from Howard. Notice their price includes shipping which is an extra $40 with some vendors.

 

https://www.ebay.com/itm/Tractor-car-6-volt-60-amp-1-wire-alternator-Positive-Ground-w-Bracket-pulley/333591006902?hash=item4dab92ceb6:g:Y~QAAMXQobdQ7d68

 

s-l225.webp

 

Edited by Sam Buchanan

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Replacing the generator may not resolve your issue.  It sounds like something is getting hot and causing the charging failure, since your ammeter appears to be working properly (shows more discharge when you turn the lights on) I wouldn't start there, wiring from the gen to the ammeter though, it could be that, heck it could just be a loose connection at the generator.  If you have an IR gun you can shoot temps of the various parts and see if anything seems out or place.  Or better yet, shoot temps before it quits, writing them down and then once it quits shoot again. 

 

Though it could be the VR or the generator anyway which the swap would fix, but I'd do some troubleshooting before i spent a lot of money.

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4 hours ago, Los_Control said:

I like to learn new things everyday, I have never heard anyone talk about converting a 12 volt alt to 6 volt. I learned something today thanks to you, I did not know when I woke up.

 

Like any troubleshooting, I figure it is best to start at the beginning, remove the VR out of the pic by disconnecting the wires, check the alternator with a multi meter to see is producing a charge. Then next step forward to connect VR and check from there.

 

I have no experience with what you are doing, but I worry about cheap china electrical parts like condensers & points, doa out of the box or work one time and condenser fails.

You drove 10 miles and it stopped working .... get the vr out of the picture and prove the alternator is charging first.

It's a .generator to begin with, all original with brand new made in USA VR. I am just curious if anyone has any experience with the 6v pos ground alternators. I did not know about the conversion kits until today, been a long time since I've had an alternator apart and even longer time since messing w/ gens and VR.

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1 hour ago, Sam Buchanan said:

 

In far less time that it would take to figure our how to redo an alternator, this reliable vendor can have an alternator that is ready to bolt to your car at your door in 3-4 days:

 

https://www.ebay.com/str/HowardEnt?_trksid=p2047675.l2563

 

I have had flawless service from the alternator I purchased from Howard. Notice their price includes shipping which is an extra $40 with some vendors.

 

https://www.ebay.com/itm/Tractor-car-6-volt-60-amp-1-wire-alternator-Positive-Ground-w-Bracket-pulley/333591006902?hash=item4dab92ceb6:g:Y~QAAMXQobdQ7d68

 

s-l225.webp

Sam that is a great price for alt/bracket/shipping. thanks

 

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1 hour ago, Sniper said:

Replacing the generator may not resolve your issue.  It sounds like something is getting hot and causing the charging failure, since your ammeter appears to be working properly (shows more discharge when you turn the lights on) I wouldn't start there, wiring from the gen to the ammeter though, it could be that, heck it could just be a loose connection at the generator.  If you have an IR gun you can shoot temps of the various parts and see if anything seems out or place.  Or better yet, shoot temps before it quits, writing them down and then once it quits shoot again. 

 

Though it could be the VR or the generator anyway which the swap would fix, but I'd do some troubleshooting before i spent a lot of money.

The generator has been checked twice(in the shop), VR new and points cleaned once already!!!??? by the electrical shop where purchased. Wiring appears OK(68 yrs. old). I will perform a load/wiggle test on the harness this week before condemning any components.

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As has been mentioned, check all your connections, and how old is your battery?

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6 hours ago, maok said:

As has been mentioned, check all your connections, and how old is your battery?

Brand new battery, new 0 gauge cables, gen checks OK, new made in USA VR, shop "cleaned points" in VR once already!!!!???? I will perform a wiggle/load test on the harness this week before I condemn any component.

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Just load tested and wiggle tested the harness, all connections OK, gen puts out when grounding field terminal. Getting money back for VR and ordered 6v pos ground alt from Howard Enterprises.

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I purchased a 6 volt positive ground 10SI self exciting alternator from these folks and a small pulley:

 

https://alternatorparts.com/6-volt-alternators-negative-positive-ground.html

 

That was 15 years ago. It has worked without issue. You MUST rev the engine after you start it up to get the thing to start charging. It uses one wire and that is it. I purchased a spare voltage regulator, which goes inside these units and have never had to touch it.

 

It has worked as my daily driver in the cold and dank San Francisco fog and at my place in the Central Valley in days of 105F heat.

 

James.

Edited by James_Douglas

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16 minutes ago, James_Douglas said:

I purchased a 6 volt positive ground 10SI self exciting alternator from these folks and a small pulley:

 

https://alternatorparts.com/6-volt-alternators-negative-positive-ground.html

 

That was 15 years ago. It has worked without issue. You MUST rev the engine after you start it up to get the thing to start charging. It uses one wire and that is it. I purchased a spare voltage regulator, which goes inside these units and have never had to touch it.

 

It has worked as my daily driver in the cold and dank San Francisco fog and at my place in the Central Valley in days of 105F heat.

 

James.

 

The one-wire alternator I have starts charging immediately after start.

 

I agree that it is a reliable solution to keeping the battery fully charged in our old cars under all conditions. A hot battery and the proper cables solves a lot of starting issues!  😁

Edited by Sam Buchanan

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