Why did some older cars have + positive grounded systems? assuming to the beginning of time most? were - negative ground.
Why did some older cars have + grounded systems?
- Thread starter JLawrence08648
- Start date
They did not know any better. Most cars and equipment was positive ground until the 50's. My 1957 tractor was originally positive ground.
Current flow doesn't care which way it goes and there is no advantage (or disadvantage) to either. That's the ultimate bottom line
The "story" goes that when things standardized, the bigger companies won. ( makes sense to me)
I've been told but question the accuracy of....
In the battery circuit, current flow is from the negative to the positive so there could be some truth to early ignition systems needing it that way for points and plugs to dissipate heat. (I can see that especially where the battery provided the spark)
I can see a little truth in the old story about retarding galvanic corrosion through cathodic protection by reversing the path but either flow the problem would still exist.
But in terms of current, I don't see where either could not be overcome so I vote the bigger company won.
The "story" goes that when things standardized, the bigger companies won. ( makes sense to me)
I've been told but question the accuracy of....
In the battery circuit, current flow is from the negative to the positive so there could be some truth to early ignition systems needing it that way for points and plugs to dissipate heat. (I can see that especially where the battery provided the spark)
I can see a little truth in the old story about retarding galvanic corrosion through cathodic protection by reversing the path but either flow the problem would still exist.
But in terms of current, I don't see where either could not be overcome so I vote the bigger company won.
Originally Posted by ragtoplvr
Why do they drive on the opposite side of the road in some countries. Some standards have science, some have practice. I do not know of any science for DC floating systems.
Rod
When I took driers training for over there with the Army, that was asked.
My class was told that in case of a heart attack, the tendency was to cut left so they drove there to not cross lanes.
Since you brought it up, I'm curious to know what others may have been told ( maybe that was the correct answer we were told)- obviously there's a reason
Why do they drive on the opposite side of the road in some countries. Some standards have science, some have practice. I do not know of any science for DC floating systems.
Rod
When I took driers training for over there with the Army, that was asked.
My class was told that in case of a heart attack, the tendency was to cut left so they drove there to not cross lanes.
Since you brought it up, I'm curious to know what others may have been told ( maybe that was the correct answer we were told)- obviously there's a reason
Originally Posted by ABN_CBT_ENGR
Originally Posted by ragtoplvr
Why do they drive on the opposite side of the road in some countries. Some standards have science, some have practice. I do not know of any science for DC floating systems.
Rod
When I took driers training for over there with the Army, that was asked.
My class was told that in case of a heart attack, the tendency was to cut left so they drove there to not cross lanes.
Since you brought it up, I'm curious to know what others may have been told ( maybe that was the correct answer we were told)- obviously there's a reason
https://en.wikipedia.org/wiki/Left-_and_right-hand_traffic
My limited reading over the years has it originating with right handed people wanting to pass on the left. Either to show no aggression--"see, my fighting hand is empty"--or to be prepared otherwise. Similar to stories about how we shake hands (which I haven't read about in a while). What would have started on foot would have migrated to horses and then naturally to cars. Quick look just now (IOW the first two or three links google came up with) indicates... no clear answer. Other than perhaps "that's just how we've always done it". Although one can never rule out trying to snub the British (we went as far as to modify our dictionary, after all).
Originally Posted by ragtoplvr
Why do they drive on the opposite side of the road in some countries. Some standards have science, some have practice. I do not know of any science for DC floating systems.
Rod
When I took driers training for over there with the Army, that was asked.
My class was told that in case of a heart attack, the tendency was to cut left so they drove there to not cross lanes.
Since you brought it up, I'm curious to know what others may have been told ( maybe that was the correct answer we were told)- obviously there's a reason
https://en.wikipedia.org/wiki/Left-_and_right-hand_traffic
My limited reading over the years has it originating with right handed people wanting to pass on the left. Either to show no aggression--"see, my fighting hand is empty"--or to be prepared otherwise. Similar to stories about how we shake hands (which I haven't read about in a while). What would have started on foot would have migrated to horses and then naturally to cars. Quick look just now (IOW the first two or three links google came up with) indicates... no clear answer. Other than perhaps "that's just how we've always done it". Although one can never rule out trying to snub the British (we went as far as to modify our dictionary, after all).
Originally Posted by supton
https://en.wikipedia.org/wiki/Left-_and_right-hand_traffic
My limited reading over the years has it originating with right handed people wanting to pass on the left. Either to show no aggression--"see, my fighting hand is empty"--or to be prepared otherwise. Similar to stories about how we shake hands (which I haven't read about in a while). What would have started on foot would have migrated to horses and then naturally to cars. Quick look just now (IOW the first two or three links google came up with) indicates... no clear answer. Other than perhaps "that's just how we've always done it". Although one can never rule out trying to snub the British (we went as far as to modify our dictionary, after all).
Very good, now
Why do we scrub down but clean up?
https://en.wikipedia.org/wiki/Left-_and_right-hand_traffic
My limited reading over the years has it originating with right handed people wanting to pass on the left. Either to show no aggression--"see, my fighting hand is empty"--or to be prepared otherwise. Similar to stories about how we shake hands (which I haven't read about in a while). What would have started on foot would have migrated to horses and then naturally to cars. Quick look just now (IOW the first two or three links google came up with) indicates... no clear answer. Other than perhaps "that's just how we've always done it". Although one can never rule out trying to snub the British (we went as far as to modify our dictionary, after all).
Very good, now
Why do we scrub down but clean up?
Years ago I heard a theory that in a positive ground system, the spark would have to jump from the negative center electrode in the spark plug to the outer electrode, which is hotter by virtue of being closer to the fire and shielding the center electrode somewhat. I realized that doesn't make much sense, because if that was a real problem, the ignition coil secondary could be wired so the negative side is the common side, and the positive side would go off to the distributor, which would make the spark jump from the outer electrode to the center. I'm pretty sure that theory was debunked anyway.
Another good question is why the British held on to positive ground long after the Yanks went to negative ground, and when the Brits finally went to negative ground, they had to keep the battery cable colors the same colors. My MG has a big warning label under the hood that it is wired "negative earth" since Midgets had been positive ground for so long, but my stock battery cables have black for positive and red for negative. It's fun going to Autozone for a battery test and having to convince them that the colors really are backward.
Another good question is why the British held on to positive ground long after the Yanks went to negative ground, and when the Brits finally went to negative ground, they had to keep the battery cable colors the same colors. My MG has a big warning label under the hood that it is wired "negative earth" since Midgets had been positive ground for so long, but my stock battery cables have black for positive and red for negative. It's fun going to Autozone for a battery test and having to convince them that the colors really are backward.
Originally Posted by ABN_CBT_ENGR
Originally Posted by supton
https://en.wikipedia.org/wiki/Left-_and_right-hand_traffic
My limited reading over the years has it originating with right handed people wanting to pass on the left. Either to show no aggression--"see, my fighting hand is empty"--or to be prepared otherwise. Similar to stories about how we shake hands (which I haven't read about in a while). What would have started on foot would have migrated to horses and then naturally to cars. Quick look just now (IOW the first two or three links google came up with) indicates... no clear answer. Other than perhaps "that's just how we've always done it". Although one can never rule out trying to snub the British (we went as far as to modify our dictionary, after all).
Very good, now
Why do we scrub down but clean up?
Why do we park in the driveway but drive on the parkway?
Sometimes truth is stranger than fiction!
I haven't a clue about your example. Maybe it's because dirt is lowly but cleanliness is next to godliness?
Originally Posted by supton
https://en.wikipedia.org/wiki/Left-_and_right-hand_traffic
My limited reading over the years has it originating with right handed people wanting to pass on the left. Either to show no aggression--"see, my fighting hand is empty"--or to be prepared otherwise. Similar to stories about how we shake hands (which I haven't read about in a while). What would have started on foot would have migrated to horses and then naturally to cars. Quick look just now (IOW the first two or three links google came up with) indicates... no clear answer. Other than perhaps "that's just how we've always done it". Although one can never rule out trying to snub the British (we went as far as to modify our dictionary, after all).
Very good, now
Why do we scrub down but clean up?
Why do we park in the driveway but drive on the parkway?
Sometimes truth is stranger than fiction!
I haven't a clue about your example. Maybe it's because dirt is lowly but cleanliness is next to godliness?
For automotive it is corrosion. For electronics in analog circuit it is because a lot of pull down circuit have higher current load than pull up circuit for the same size / cost, so a lot more circuits are using pull down transistors and amplifiers, that's why electronics on PCB typically are - ground instead of + ground.
Originally Posted by Dave Sherman
Years ago I heard a theory that in a positive ground system, the spark would have to jump from the negative center electrode in the spark plug to the outer electrode, which is hotter by virtue of being closer to the fire and shielding the center electrode somewhat. I realized that doesn't make much sense, because if that was a real problem, the ignition coil secondary could be wired so the negative side is the common side, and the positive side would go off to the distributor, which would make the spark jump from the outer electrode to the center. I'm pretty sure that theory was debunked anyway.
Another good question is why the British held on to positive ground long after the Yanks went to negative ground, and when the Brits finally went to negative ground, they had to keep the battery cable colors the same colors. My MG has a big warning label under the hood that it is wired "negative earth" since Midgets had been positive ground for so long, but my stock battery cables have black for positive and red for negative. It's fun going to Autozone for a battery test and having to convince them that the colors really are backward.
Besides, electrons jump from negative to positive and are negatively charged...
Years ago I heard a theory that in a positive ground system, the spark would have to jump from the negative center electrode in the spark plug to the outer electrode, which is hotter by virtue of being closer to the fire and shielding the center electrode somewhat. I realized that doesn't make much sense, because if that was a real problem, the ignition coil secondary could be wired so the negative side is the common side, and the positive side would go off to the distributor, which would make the spark jump from the outer electrode to the center. I'm pretty sure that theory was debunked anyway.
Another good question is why the British held on to positive ground long after the Yanks went to negative ground, and when the Brits finally went to negative ground, they had to keep the battery cable colors the same colors. My MG has a big warning label under the hood that it is wired "negative earth" since Midgets had been positive ground for so long, but my stock battery cables have black for positive and red for negative. It's fun going to Autozone for a battery test and having to convince them that the colors really are backward.
Besides, electrons jump from negative to positive and are negatively charged...
Originally Posted by Jetronic
Besides, electrons jump from negative to positive and are negatively charged...
This.
BTW, my '65 Chrysler four-door hardtop I bought in the '90s had left-hand wheel-lug threads on the driver's side. That was gone by the '70s.
And did you ever see a house fly and a barn dance? I think not!
Besides, electrons jump from negative to positive and are negatively charged...
This.
BTW, my '65 Chrysler four-door hardtop I bought in the '90s had left-hand wheel-lug threads on the driver's side. That was gone by the '70s.
And did you ever see a house fly and a barn dance? I think not!
Last edited:
Originally Posted by Dave Sherman
Another good question is why the British held on to positive ground long after the Yanks went to negative ground, and when the Brits finally went to negative ground, they had to keep the battery cable colors the same colors. My MG has a big warning label under the hood that it is wired "negative earth" since Midgets had been positive ground for so long, but my stock battery cables have black for positive and red for negative. It's fun going to Autozone for a battery test and having to convince them that the colors really are backward.
My 70 B was converted to single battery long before I bought it, but the original ground strap and cross-over cable are still hiding down there in the battery wells and AFAIK the positive lead to the starter is original. All are black.
My ground strap is new, but a generic Autozone replacement. I have colored plastic covers over both terminals to indicate polarities.
BTW, MGs(or at least MGBs) went negative earth in 68 with the Mark II. That was also when they switched from dynamos to alternators, and presumably that was a large part of the drive to switch-otherwise I wouldn't be surprised if they'd held out on positive to the end.
What's also interesting to me is that even back in the 40s with the T-type MGs(and also with Mogies I've played with) the Brits were using 12V when American and Germans were largely using 6V. A lot of folks will mistake MGAs and pre-74 MGBs as 6V systems since they originally used 2 6V in series, but they were in fact 12V and I don't know of many people who still run 6V batteries. A 26R drops right into an MGB with higher CCAs and less weight than "original style" tar tops that are also shipped dry and have to be filled before use. Plus, you get to ditch the cross-over cable that can be a problem.
Another good question is why the British held on to positive ground long after the Yanks went to negative ground, and when the Brits finally went to negative ground, they had to keep the battery cable colors the same colors. My MG has a big warning label under the hood that it is wired "negative earth" since Midgets had been positive ground for so long, but my stock battery cables have black for positive and red for negative. It's fun going to Autozone for a battery test and having to convince them that the colors really are backward.
My 70 B was converted to single battery long before I bought it, but the original ground strap and cross-over cable are still hiding down there in the battery wells and AFAIK the positive lead to the starter is original. All are black.
My ground strap is new, but a generic Autozone replacement. I have colored plastic covers over both terminals to indicate polarities.
BTW, MGs(or at least MGBs) went negative earth in 68 with the Mark II. That was also when they switched from dynamos to alternators, and presumably that was a large part of the drive to switch-otherwise I wouldn't be surprised if they'd held out on positive to the end.
What's also interesting to me is that even back in the 40s with the T-type MGs(and also with Mogies I've played with) the Brits were using 12V when American and Germans were largely using 6V. A lot of folks will mistake MGAs and pre-74 MGBs as 6V systems since they originally used 2 6V in series, but they were in fact 12V and I don't know of many people who still run 6V batteries. A 26R drops right into an MGB with higher CCAs and less weight than "original style" tar tops that are also shipped dry and have to be filled before use. Plus, you get to ditch the cross-over cable that can be a problem.
Originally Posted by supton
one can never rule out trying to snub the British (we went as far as to modify our dictionary, after all).
But kept their measuring system ? I think that would be the first stupid thing to get rid of.
The British cars generally changed to negative earth when they went from generators to alternators. Triumph motorcycles had an alternator in 1953, positive earth, so they knew about them for sure. Most were 12 volt, just the small Fords hung on to 6 volt - transverse springs, mechanical brakes, sidevalve engines....they were really just small American Fords. Until recently trucks would often have 4 separate 6 volt batteries, 2 12 volts these days for 24 volt systems.
Going from pos to neg earth was just a flick on the F terminal of the generator...and swap the coil leads too.
one can never rule out trying to snub the British (we went as far as to modify our dictionary, after all).
But kept their measuring system ? I think that would be the first stupid thing to get rid of.
The British cars generally changed to negative earth when they went from generators to alternators. Triumph motorcycles had an alternator in 1953, positive earth, so they knew about them for sure. Most were 12 volt, just the small Fords hung on to 6 volt - transverse springs, mechanical brakes, sidevalve engines....they were really just small American Fords. Until recently trucks would often have 4 separate 6 volt batteries, 2 12 volts these days for 24 volt systems.
Going from pos to neg earth was just a flick on the F terminal of the generator...and swap the coil leads too.
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