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curt
02-12-2007, 08:20 PM
When did Studebaker change to POS ground? When they went to a 12 volt generator in 1956? Later?

whacker
02-12-2007, 08:25 PM
Before 1956, all American cars were 6 volt, positive ground. When most US automakers changed to 12 volts in 1956, they also changed to negative ground. Only a few foreign cars (MG for one) ever had 12 volt positive ground.

John Kirchhoff
02-12-2007, 10:11 PM
I find that odd because farm equipment used 12V positive ground generator systems up into the early to mid 60's.

dictator27
02-12-2007, 10:20 PM
Just about any British car was 12v + into the 60's. Before WW2 Studebakers made for the British market were 12v +.

Terry

"If you can keep a cool head whilst all the others around are losing theirs, perhaps you just don't understand the situation."

John Ratliff
02-12-2007, 11:05 PM
Studebaker went to 12V Negative ground in '56. General Motors had 12V negative ground on all but Chev. in '54. Chev changed in '55. G.M. was negative ground on their 6V cars before going to 12V. Ford, GM and Chry. changed in '56.

John Ratliff
http://static.flickr.com/102/302372902_63249ab71a_m.jpg

Skip Lackie
02-13-2007, 09:10 AM
quote:Originally posted by John Ratliff

Studebaker went to 12V Negative ground in '56. General Motors had 12V negative ground on all but Chev. in '54. Chev changed in '55. G.M. was negative ground on their 6V cars before going to 12V. Ford, GM and Chry. changed in '56.

John Ratliff



A minor addition: While the above is true for the early 50s, some of the GM brands were 6V negative ground and some were positive until WWII. I think Cadillac (for one) was 6V positive ground till 1948. This was in the days when GM divisions shared very little except basic body shells. I'm old enough to remember the 1950s, when being asked to jump start a complete stranger's car was a very common occurrence. I learned the hard way that you had to be very careful to determine if the dead car was positive or negative ground, especially when jumping a dead 6v battery with 12 volts.[:0]

Skip Lackie
Washington DC

curt
02-13-2007, 12:30 PM
Thanks for the input. Studebaker went neg ground in 1956 with its change to 12 volts in 1956. When electrons flow from negative to positive it has always seemed that pos ground would be the way to go.??[?]

Studenut
02-13-2007, 02:33 PM
A possible reason for adopting negative gnd. was that for a brief period in the mid 50's, before radios became completely transistorized, there were car radios that used special audio output tubes that ran with only 12 volts on the plates. But this would have to be a positive voltage with respect to gnd. (to attract the electrons across the tube) so therefore, the system gnd. would have to be negative.

Jerry Buck
Racine, Wisconsin
'53 Champion Coupe - C (owned since 1956)
'61 Lark VI Convertible

StudeRich
02-14-2007, 02:20 AM
I don't think so...Diodes only work with negative ground. All of the transistor radios in 1963 and up cars and electronic gadgets we now have in our newer cars would NOT work!


quote:Originally posted by curt

When electrons flow from negative to positive it has always seemed that pos ground would be the way to go.??[?]


StudeRich
Studebakers Northwest
Ferndale, WA

John Kirchhoff
02-14-2007, 09:53 AM
Yes it's true that alternators with diodes only work as negative ground, but in electronics (tv's, computers, radios, ect) electrons actually flow from negative to positive. Yeah I know, that doesn't make sense and is opposite what you were taught in auto mechanics, but there's a lot of things in this world that don't make sense or seem reasonable.