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39DodgeD11

positive ground battery system??

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can someone explain to me exactly what a positive ground battery system is? Does it mean the positive cable on the car goes to the negitive terminal on the battery and neg cable goes to positive terminal? Ive heard some talk about it since coming on here but i guess ive really never looked into it.

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Positive ground means that the cable attached to the positive post on the battery (the big one) attaches to GROUND (the engine block, and a smaller braided strap to the chassis/body) on the other end and the NEGATIVE cable runs from the negitive post on the battery (smaller) goes to the starter solenoid, where that current is distributed to the starter when the solenoid is engaged, and the various tap-offs that terminate at the starter soleniod.

When you install the battery you still hook the large terminal to positive and the small terminal to negitive.

A lot of old cars are monkyed with re: positive ground because it hasn't been the standard for 50+ years and some folks just can't get their heads around the basic idea.

Trace where each cable is connected.

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Essentially it means the battery is installed "backwards". The positive terminal is the ground and the negative terminal is the live.

Many cars were set up this way. All Ford, Chrysler and Hudson cars and all English cars for a start.

It makes no difference at all to the car, except that certain parts are polarity sensitive such as the radio and the ammeter. These parts are made to get their power in a particular way. So just put the battery in the way the maker intended.

In the beginning when they first started making cars someone had to decide which way round to put the battery. Some chose one way, some the other.

There is only one good reason I know to prefer one over the other. If you notice, on your cars the positive terminal always gets nasty and corroded and covered in icky green guck first.

They figured if one cable was going to get all corroded and rot off it better be the ground because it was easiest and cheapest to replace. So they made the battery positive ground.

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Don't forget about having to polarize the generator. When I got my DA the previous owner said that there was something wrong with the charging system, as it would read a discharge as the engine RPM was increased. Everything in the system checked out fine, polarized the generator, no more problem.

And not "all" Ford cars were positve ground. They built more than a few between 1919 and 1927 that were negative ground, the model T.

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Don't forget about having to polarize the generator. When I got my DA the previous owner said that there was something wrong with the charging system, as it would read a discharge as the engine RPM was increased. Everything in the system checked out fine, polarized the generator, no more problem.

And not "all" Ford cars were positve ground. They built more than a few between 1919 and 1927 that were negative ground, the model T.

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not all English cars were either , i have owned Austins .Morris, Vauxhall and Landrovers and they were all neg ground . although there were some years of landrover that were positive ground.

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not all English cars were either , i have owned Austins .Morris, Vauxhall and Landrovers and they were all neg ground . although there were some years of landrover that were positive ground.

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Just as in North America, most of the British cars up through the 1950's were positive ground, although 12-volt was more common. And, just as in North America, Britain switched to negative ground.

To show how things changed over the years :

1930 : positive ground -

Auburn, Cadillac, Chrysler, DeSoto 8, Dodge, Erskine, Ford, Graham, Hupmobile, LaSalle, Nash (except 6-450), Packard, Studebaker, Willys, Willys-Knight

1930 : negative ground -

Buick, Chevrolet, DeSoto 6 (switched to positive 1931), Durant, Essex, Hudson (switched to positive 1934), Marquette, Nash (6-450), Oakland, Oldsmobile, Plymouth (switched to positive in 1931), Pontiac, Reo

1950 : positive ground -

Chrysler, Crosley, DeSoto, Dodge, Ford, Frazer, Hudson, Kaiser, Lincoln, Mercury, Meteor, Monarch, Nash, Packard, Plymouth, Studebaker, Plymouth

British - Austin, Ford, Hillman, Humber, Jaguar, MG, Morris, Riley, Rover, Standard, Sunbeam-Talbot, Triumph, Vauxhall

1950 : negative ground -

Buick, Cadillac, Chevrolet, Oldsmobile, Pontiac, Willys

1965 : positive ground -

Austin, Datsun, Envoy, Ford (GB), Hillman, Humber, Jaguar, MG, Morris, Riley, Rover, Singer, Sunbeam, Triumph, Vauxhall

1965 : negative ground -

Acadian, BMW, Buick, Cadillac, Checker, Chevrolet, Chrysler, Citroen, Dodge, Fiat, Ford, Ford (German), Honda, Isuzu, Imperial, Lincoln, Mercedes-Benz, Mercury, Meteor, NSU, Oldsmobile, Opel, Peugeot, Plymouth, Pontiac, Porsche, Rambler, Renault, Simca, Skoda, Studebaker, Toyota, Valiant, Volkswagen, Volvo

The last of the positive ground cars switched to negative -

Austin - started switch in 1971

Datsun - 1966

Envoy - 1967

Ford (GB) - 1967

Hillman - 1966

Humber - 1966

Jaguar - 1967 to 1969

MG - 1969

Morris - dropped

Riley - dropped

Rover - 1969

Singer - 1966

Sunbeam - 1966

Triumph - 1967

Vauxhall - 1967

Bill

Vancouver, BC

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Just as in North America, most of the British cars up through the 1950's were positive ground, although 12-volt was more common. And, just as in North America, Britain switched to negative ground.

To show how things changed over the years :

1930 : positive ground -

Auburn, Cadillac, Chrysler, DeSoto 8, Dodge, Erskine, Ford, Graham, Hupmobile, LaSalle, Nash (except 6-450), Packard, Studebaker, Willys, Willys-Knight

1930 : negative ground -

Buick, Chevrolet, DeSoto 6 (switched to positive 1931), Durant, Essex, Hudson (switched to positive 1934), Marquette, Nash (6-450), Oakland, Oldsmobile, Plymouth (switched to positive in 1931), Pontiac, Reo

1950 : positive ground -

Chrysler, Crosley, DeSoto, Dodge, Ford, Frazer, Hudson, Kaiser, Lincoln, Mercury, Meteor, Monarch, Nash, Packard, Plymouth, Studebaker, Plymouth

British - Austin, Ford, Hillman, Humber, Jaguar, MG, Morris, Riley, Rover, Standard, Sunbeam-Talbot, Triumph, Vauxhall

1950 : negative ground -

Buick, Cadillac, Chevrolet, Oldsmobile, Pontiac, Willys

1965 : positive ground -

Austin, Datsun, Envoy, Ford (GB), Hillman, Humber, Jaguar, MG, Morris, Riley, Rover, Singer, Sunbeam, Triumph, Vauxhall

1965 : negative ground -

Acadian, BMW, Buick, Cadillac, Checker, Chevrolet, Chrysler, Citroen, Dodge, Fiat, Ford, Ford (German), Honda, Isuzu, Imperial, Lincoln, Mercedes-Benz, Mercury, Meteor, NSU, Oldsmobile, Opel, Peugeot, Plymouth, Pontiac, Porsche, Rambler, Renault, Simca, Skoda, Studebaker, Toyota, Valiant, Volkswagen, Volvo

The last of the positive ground cars switched to negative -

Austin - started switch in 1971

Datsun - 1966

Envoy - 1967

Ford (GB) - 1967

Hillman - 1966

Humber - 1966

Jaguar - 1967 to 1969

MG - 1969

Morris - dropped

Riley - dropped

Rover - 1969

Singer - 1966

Sunbeam - 1966

Triumph - 1967

Vauxhall - 1967

Bill

Vancouver, BC

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My '22 DB touring was definitely 12-volt negative ground from the factory. I looked it up in the instruction book.

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My '22 DB touring was definitely 12-volt negative ground from the factory. I looked it up in the instruction book.

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They built a few (million) Model Ts that were 24 volt AC too.

I was trying to answer the man's question not write an encyclopedia. But thanks for the information guys.

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They built a few (million) Model Ts that were 24 volt AC too.

I was trying to answer the man's question not write an encyclopedia. But thanks for the information guys.

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Model T running on magneto, yes AC, the voltage depends on engine RPM and strength of magnets. Model T running on battery, 6 volt.

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Model T running on magneto, yes AC, the voltage depends on engine RPM and strength of magnets. Model T running on battery, 6 volt.

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I was trying to answer the man's question not write an encyclopedia

Now thats funny

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I was trying to answer the man's question not write an encyclopedia

Now thats funny

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Bill-W The Vauxhall's i have owned were a 1948 J model which i owned for 12 yrs and a 1969 PC cresta 17yrs both were neg ground , my austin was a 1936 AUSTIN 7 about 5 yrs, it was neg ground , my Morris was a late 60's morris 1300 also neg ground. i dont live in the US perhaps the North American export models were different than the British domestic models and those exported to Australia ,New Zealand ,India etc

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Bill-W The Vauxhall's i have owned were a 1948 J model which i owned for 12 yrs and a 1969 PC cresta 17yrs both were neg ground , my austin was a 1936 AUSTIN 7 about 5 yrs, it was neg ground , my Morris was a late 60's morris 1300 also neg ground. i dont live in the US perhaps the North American export models were different than the British domestic models and those exported to Australia ,New Zealand ,India etc

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When I say "all Fords were + ground etc" please don't take me too literally. By all Fords I mean all Ford made cars including Mercury and Lincoln.

American cars standardised on 12 volt negative ground starting in 1955 or 56. Some did this earlier. I have heard of a 1953 Cadillac limousine that was half 6 volt, half 12 and it supposedly came that way from the factory.

English cars adopted negative ground in 1969 although not all cars changed over in 1969. Most had been 12 volt + ground for years although there were exceptions.

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When I say "all Fords were + ground etc" please don't take me too literally. By all Fords I mean all Ford made cars including Mercury and Lincoln.

American cars standardised on 12 volt negative ground starting in 1955 or 56. Some did this earlier. I have heard of a 1953 Cadillac limousine that was half 6 volt, half 12 and it supposedly came that way from the factory.

English cars adopted negative ground in 1969 although not all cars changed over in 1969. Most had been 12 volt + ground for years although there were exceptions.

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ok thanks, i will trace cables in a week or 2 when i get it out of storage!

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ok thanks, i will trace cables in a week or 2 when i get it out of storage!

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Just as a final thought you all seem to forget the most prevalent 6 volt,positive ground, car ever made: the Volkswagen Type 1 Beetle. I think there was more Beetles made than Model Ts.

Also ALL British Vehicles imported after WWII were 12 volt positive ground. I owned several Rootes and BMC types and all were positive ground. I remember distinctly having to flip jumper cables while trying to jump start any of my cars during the 50s or early 60s.By 1971 my new MGBGT was 12 volt negative ground. MGs had two 6 volt batteries,one on each side of the drive tunnel under the rear seat,hooked in series for 12 volts but negative ground. I remember that very well as I bought and installed one of those Bell transistorized capacitve discharge ignition systems.

I do not know when the change over took place in British cars but no Hillman or Morris or Sunbeam I ever owned had negative ground.

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Amphicars, German-built during the mid 1960's, all had 12-v pos gnd. They featured an 1145cc Triumph Herald engine. It was underpowered for the road, but overpowered for the dual plastic props.

My '55 Ford was built with 6-v pos. gnd., as was a host of other cars.

Not to say any system is better than another, thank God '55 was the last year Ford used both 6-volt AND positive ground. Trying to sell my old 6-v parts is futile. The same parts in 12-v brings much more money (like a heater motor).

Standardization proved essential for the entire industry. ...ever try finding a decent radio (or anything else) in either 6-volt or positive ground?

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