6 or 12V

1941 - 1945, MB, GPW Technical questions and discussions, regarding anything related to the WWII jeep.
GSS
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Re: 6 or 12V

Post by GSS » Thu Nov 18, 2021 4:05 pm

6 volt struggles even at 5C in balmy Minnesota….can’t even imagine trying to start it at 5F. I have 6V in my slat to keep it original, but kept the 12V that a previous owner had installed in my 45. Definitely a lot more reassuring knowing that it will start when you aren’t close to home.
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Re: 6 or 12V

Post by raymakr » Thu Nov 18, 2021 10:44 pm

I went 12 volt. My six volt fired up and ran okay but I hated the floor starter. My first MB Jeep started off a keyed dash switch. Call me lazy. I was searching for a six volt solenoid to just add a keyed dash switch when I ran into a NOS 12 volt voltage regulator at a show that worked. I then set about finding the rest of the parts. I found a WW2 generator that was converted to 12 volts and fits perfectly looking six volt. Bought a new 12 volt starter, from Ron Fitzpatrick 12 volt coil with internal ballast resistor, front headlights and a few other items. I bought LED lights made by Paul Fitzgerald at a Jeep show. You can use drop down resistors for the gas gauge and fender black out lights. On mine I have a starter solenoid under the oil bath so I can start off the floor or the dash. I had red tags made for my electrical components. I bought the antique auto battery which is close to a ww2 case. So anyone looking at my motor thinks its six volts. It even fooled the Jimmy Strauss crew that thought it six volt till I fired it up. If you go the VR and generator route make sure the generator is on a B circuit, to match the VR. JMP makes the new solid state VR switchable from six to twelve volts, if you want the original look. You could save money by using a one wire alternator thereby cutting out the cost of a Voltage regulator. I used my 12 volt Jeep for living history and was headed out to the field those cold mornings, while my six volt buddies were still cranking over their motors. The only thing you might miss is that famous chug chug of a six volt system starting up. Good luck.

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Re: 6 or 12V

Post by conrod6 » Thu Nov 18, 2021 10:54 pm

Nice video - real nice 6v start

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Re: 6 or 12V

Post by YLG80 » Thu Nov 18, 2021 11:37 pm

Bangle 99 wrote:
Thu Nov 18, 2021 3:46 pm
Here’s how your 6v system should work.
https://youtu.be/mo_5cNLqh0A
Waooh, is this is a brand new battery?
My 6V/110Ah battery is in its 7th year, likely close to end of life, and believe me the cranking is muuuuch slower than that , although its starts without any problem.
If its a new battery in your video, I'm sure I need to change my battery right now... :o
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Re: 6 or 12V

Post by Paolo.orange » Fri Nov 19, 2021 3:08 am

I have a 6V and no problem in winter in Milan.
I found that a very good ground and oversized positive cables are the keys for a reliable 6V system.
Paolo - Milan, Italy
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Re: 6 or 12V

Post by Bangle 99 » Fri Nov 19, 2021 5:27 am

conrod6 wrote:Nice video - real nice 6v start

Barrie
Thank you. I’m proud of it.



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Re: 6 or 12V

Post by Bangle 99 » Fri Nov 19, 2021 5:28 am

YLG80 wrote:
Bangle 99 wrote:
Thu Nov 18, 2021 3:46 pm
Here’s how your 6v system should work.
https://youtu.be/mo_5cNLqh0A
Waooh, is this is a brand new battery?
My 6V/110Ah battery is in its 7th year, likely close to end of life, and believe me the cranking is muuuuch slower than that , although its starts without any problem.
If its a new battery in your video, I'm sure I need to change my battery right now... :o
Yves
It’s a 6v Optima in a case made by Rob Lentz back when he was making them and selling them on here.



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Re: 6 or 12V

Post by twinflyer17 » Fri Nov 19, 2021 6:38 am

My only recommendation is that if you want to keep your jeep looking mostly original, at least use a generator over an alternator if you plan to go 12v. My jeep is 12v only because I bought it with a working 12v generator that looks very close to the original 6v generators. I have a modern 12v regulator in an original 6v regulator housing, and the 12v battery doesn't look all that out of place. I plan to convert back to original 6v at some point, but for what that's likely to cost me, why fix what ain't broke? :wink:
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Re: 6 or 12V

Post by dpcd67 » Fri Nov 19, 2021 6:59 am

Milan is just across the river from me, and it gets to -20 F in January. No way a 6 volt will start if it has been sitting outside. Oh, I mean Milan Illinois.
I once started my M37 sitting outside, at a actual minus 17, it was a sunny morning, and it started well. My 42 GPW, with all new or rebuilt components; would barely turn over.
There is a reason we no longer use 6 volts in cars. And the Army basically went directly from 6 to 24 volt. Sure, all you guys who live in warm climates, and keep your jeeps in doors, they will start.
And 32 degrees is warm. We don't use centigrade here. In Minnesota when it gets up to 32, they go sun bathing.
Now, when I restore a vehicle, it goes back to original configuration in every way. But I don't drive them in the winter either. Tons of salt on the roads is the main reason. No heater is the other. Too darn cold is the real reason.
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Re: 6 or 12V

Post by Bangle 99 » Fri Nov 19, 2021 7:16 am

The reason we went from 6v to 12v was to meet the growing demands for electronics in vehicles.



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Re: 6 or 12V

Post by mdainsd » Fri Nov 19, 2021 7:27 am

Larger displacement plus high performance and higher compression due to the introduction of overhead valves is why the transition was made from 6V to 12V from 1955 through 1956. Other than power windows and seats, electronics was in the distant future.
52 M38 2X, '52 M37, '44 WC51, '42 WC 56/57, '50 CJ-V35(U), '42 GPW, '44 M3A1 Scout Car, 2010 M-Gator

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Re: 6 or 12V

Post by Adam » Fri Nov 19, 2021 8:14 am

I have 6 volts in the mb that i drive ocassionaly in the summer, the cj2a that i use year round, has 12 volts, and a 12 volt starter that is just a forklift starter that has had the holes ovaled out, came from macs jeep parts out in oregon or washington 20 years ago,, still going. Now the MB will start with no issues down to 20 or so with the oil thinned out, block was clean so no crud will get into the bearings from washing effect, now just need to change the air filter oil as last night it was 17 and it is thick as molases.


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Re: 6 or 12V

Post by DogDoc » Fri Nov 19, 2021 8:24 am

I don't know about y'all but my GPW has power windows and door locks.
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Re: 6 or 12V

Post by tamnalan » Fri Nov 19, 2021 8:45 am

To me the best reason to convert to 12v is so heat pads can be sewn into the seats.

Nothing like a great set of bun warmers under that canvas on a cold day...
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Re: 6 or 12V

Post by irakli » Fri Nov 19, 2021 9:45 pm

The key is good ground (there was tinning for a reason), correct positive wires and 6v Optima battery. Optima is full of juice even when temp is close to 30°. I converted from 12V back to 6V and hardly feel any difference.
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