Whenever working on a vehicle, and you look at the manual, it always says first to disconnect the ground terminal from the battery. What is the difference if you removed instead the Positive side, doesn't that remove the power as well ?
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Whenever working on a vehicle, and you look at the manual, it always says first to disconnect the ground terminal from the battery. What is the difference if you removed instead the Positive side, doesn't that remove the power as well ?
it does remove the power as well but you should disconect the negitive first because if your wrench or whatever tool you are using to disconnect the battery come in contact with another metal part such as a fender it will not arc. if your wrench is on the positive side and this happens you will have an arc and could hurt yourself or the electronics in the car.
Actually if you study electricity you will know that the positive terminal on a battery is actually negative, and the negative terminal is positive. So the electricity flows from the negative terminal to the positive one. I hope that answers your question even though it is very confusing.
That definitely makes sense to me, seeing as how everything else on a vehicle(a vehicle that you're trying to work on anyway) is upside down and backwards too ; )Quote:
Originally Posted by jghilino
yea its similar to the welding we do, we reverse polarity when we switch from tig to smaw when were welding out tubes, stick welding electrode positive, tig welding its negative. Some times i even have to think about it for a minute or 2 to figure it out.
its negative to positive when resistance is applied as i said earlier
How do batteries work?
As a former electrician, I can tell you that the electricity outside the battery flows from postitive to negative. I just think you are getting mixed up between the flow inside and outside of the battery.
And I've seen what can happen when someone gets hit from DC current.
"The electron was discovered in 1897 and it was found to have a negative charge. The guess made in the early days of electricity was wrong! Electricity in almost all conductors is really the flow of electrons (negative charge) from - to +." That is why you always disconnect the negative terminal as that is where the flow of electrons comes from because they are negatively charged.
Okay. You are right and I am wrong. 30 years working as an electrician and I just don't know what I'm talking about. Sorry.
On a related note, I have heard that you don't want vehicles to be touching when doing a jump, but don't know why?
I was taught to disconnect the negative first too. This is from cartalk:
It was already said but I'd give you a more detailed explanation. If you
touch positive to negative battery post with a piece of metal it will create
a circuit (a short--dangerous). As you know the negative cable on the
battery is connected to the metal part of your car (body). If you touch the
positive post of the battery to a metal section on the car it will be the
same as touching the positive terminal of the battery to the negative which
will create a short. If you remove the negative cable first, now the metal
part of the car is not connected to the battery in any way, so even if you
touch any part of the car's body while you're messing with the positive
post, it won't short out and do nasty things (best case you'll get some
sparks and that would be it). If you're removing the positive cable first
and the negative cable hasn't been disconnected from the car body, and you
touch the metal of the car with your wrench while you're unscrewing the
positive connector, you might get shocked if there's no isolation on the
wrench. That's why people recommend removing the negative terminal first.
Now if you don't touch any part of the body with your wrench while you're
touching the positive terminal, you have nothing to worry about.
Hope this helps.
--Viktor
lol i would imagine ive done it half the time right and half the time wrong
i like that answer the best, its a lot less confusing than reading all those articlesQuote:
Originally Posted by freonjoe
I was taught to disconnect the one that conect to the body first. This was more of a safty thing like freonjoe posted.
Just to confuse you young guys. You know some cars had the positive conected to the body no the negative. Then some were 6 volt systems too.
Back when I was taught it was because some cars were positive ground and some negative ground.Quote:
Originally Posted by IdahoScrapper
every now and then i still run across one there are some people out there that have their antique all original and still a positive ground system. we had a 53 ford F3 in the shop a few weeks ago the kid working on it was having a hell of a time, couldnt get his test light to work right or anything lol but then again same kid i had to go show how to operate a standard colum shift in an old Chevy IIQuote:
Originally Posted by ron22
When 'jump starting' a car. Connect the earth lead to the engine of the car being started.
First, theres less metal for the power to go thru to get to the starter.
Second, if you make a connection close to the battery, while its being charged, the battery is making hydrogen gas. By connecting the lead to the engine, the sparks not beside the battery & it won't ignite the gas.
Battery explosions, a close second the exploding/(imploding) CRT screens. With acid.....