Black Positive Cable = FUUUCKKK YOUUU!

[jonmon6691]

There's a lot of misinformation in this thread about electronics ("reverse the battery's polarity" seriously?) From what I've read here before, hooking the battery up backwards causes a lot of damage even if for just a moment, let alone 30 seconds + trying to start it.

[mamzak]

There's a lot of misinformation in this thread about electronics ("reverse the battery's polarity" seriously?) From what I've read here before, hooking the battery up backwards causes a lot of damage even if for just a moment, let alone 30 seconds + trying to start it.

haha I just googled "hooking up a car battery backwards" and someone said that if left long enough if would reverse the battery or something. So what am I going to need to do to get this thing back on the road? Trace all my wires and look for shorts, replace the alternator, starter?

[daniel]

it's the alternator

[xwill112x]

ive hooked my 318 up backwards before, didnt hurt it.

[mamzak]

ive hooked my 318 up backwards before, didnt hurt it.

How long did you have it hooked up? Did it give you troubles starting afterwards?

[Matt-B]

did you put battery in wrong way then, cause i cant get my cables mixed up...to short lol

[xwill112x]

How long did you have it hooked up? Did it give you troubles starting afterwards?

i tryed to start it, then was like "doh wtf, just put the battery in backwards, " so i fixed it and it started up fine.

[mamzak]

i tryed to start it, then was like "doh wtf, just put the battery in backwards, " so i fixed it and it started up fine.

huh. well that sucks.. because mine was definitely giving me some shit.

[MikeDE]

That's funny, I was looking at mine today while I was cleaning my trunk and thought, "How much would it suck if I hooked them up backwards?". Well now I know.

[evil_twin]

maybe you shouldn't be working on cars... because the cables are kind of hard to hook up backwards on the battery since they are pretty much molded a certain way. I can see hooking it up backwards when you jumpstart the car, but not when you're putting the battery back in.

[DJB]

The original poster thought that the previous owner had installed a black positive cable.

The positive cable came that way from the factory. Along with a brown negative cable that can easily be mistaken for red.

And many, many people have made that mistake. Even those of us who know better...

This was clearly stupid on BMW's part. They might assert that brown is their standard color coding for ground, and black is sometimes used for hot (e.g. high voltage wiring).
But it would have been trivial to put a red marker around the end of the positive cable.

[b*saint]

blue and brown are european + -

[evil_twin]

Actually... it's not stupid on BMWs part. If you think about it, NORMAL HOME electricity they use black for positive and white for negative. Now I know this isn't home electricity, but wires can be what ever color the installer wants it to be.

[Jean]

Actually... it's not stupid on BMWs part. If you think about it, NORMAL HOME electricity they use black for positive and white for negative. Now I know this isn't home electricity, but wires can be what ever color the installer wants it to be.

Last time I checked home electricity had AC current and not DC ;)

[evil_twin]

You sir are correct. But that has nothing to do with my point. :-p