Battery replacement issue (big one)

"Henry Bemis" > wrote in message
t...
> Hee hee! I did this once (and only once!). It was on my 56 Chevy. Dang
thing
> started up and the only clue it was backwards was the 8 track chewed the
sh*t
> out of my Arlo Guthrie tape from Columbia House!
>

It wasn't backwards - that was just the 8 track drive taking the opportunity
to
get rid of an extremely obnoxious tape. ;-)

Ted

On 07/14/07 10:57 pm Ron Seiden wrote:

>> Thats exactly what I thought it sounded like, but the thing is I put
>> the battery cables on just like the old battery had them on, the weird
>> thing I was thinking of was the negative cable connected to the left
>> side of that red post that the positive connects to the other side, is
>> that correctly done? Maybe the old battery just didnt have enough
>> juice to give this reaction?

> Umm, generally red is the positive terminal and black is the negative,
> regardless of where they are on the battery. No matter what, every auto
> battery has a "+" and "-" marked next to the relevant terminals. Forget
> about "doing like it used to look" -- just do it right.
>
> If you did connect it backwards, there's a chance you've fried the
> electronic brain (which would explain the weird behavior)....


I fried the diodes in an alternator of a friend's old car when I
replaced the battery. I connected the red battery lead to the +ve
terminal and the black to the -ve -- only to find out later that the red
lead on this vehicle was the ground; I assume that's not the way it came
from the manufacturer.

Perce

"afx" > wrote in message
ps.com...
> >
> > Thank Chrysler for putting safe guards on their vehicles,
> > otherwise you'd be posting with a face full of battery acid.
>
> I appreciate that. /sarcasm
>

Actually, all kidding aside, you SHOULD appreciate that.

It's tough to protect the vehicle. The master fusible link needs to pass
so much current in normal operation that it can't be expected to protect
the vehicle components from something like a reversed battery.

What it does is protect you.

Seriously, a shorted battery very often WILL explode. The least of
your worries at that point would be cleaning acid off from everything
in the engine compartment. You should be more concerned with
at least your eyes (battery acid in the eyes is almost instantly blinding,
and pretty much usually permanently) and the explosion could be fatal
to leaning right over hooking up the thing.

"Henry Bemis" > wrote in message
t...
> Hee hee! I did this once (and only once!). It was on my 56 Chevy. Dang
thing
> started up and the only clue it was backwards was the 8 track chewed the
sh*t
> out of my Arlo Guthrie tape from Columbia House!
>

Years ago I had a 1950 Willy's. Now, I didn't do it, but someone I know
said they actually had their Willys try to turn over backwards when things
got reversed. Allegedly there was no damage.

afx wrote:
> On Jul 14, 6:12 pm, Bill Putney > wrote:
>
>>afx wrote:
>>
>>>...the negative cable connected to the left
>>>side of that red post that the positive connects to the other side, is
>>>that correctly done?...
>>
>>Negative = black; positive = red (the opposite of the convention used in
>>economics).
>>
>>Bill Putney
>>(To reply by e-mail, replace the last letter of the alphabet in my
>>address with the letter 'x')
>
>
> here are the pics.
>
>
> http://s208.photobucket.com/albums/b...=IMAGE_006.jpg
> pic of the cables in general including the thick black one I replaced
> that I connected to negative.
>
> http://s208.photobucket.com/albums/b...=IMAGE_007.jpg
> Auxiliary cable that got severed
>
> http://s208.photobucket.com/albums/b...=IMAGE_008.jpg
> Picture of the positive battery terminal on the positive side of the
> battery.
>
>
> Hope this helps!

Heck - I might as well pile on with everybody else.

The big cable in your first photo that you connected to the negative
terminal - that is your positive lead. The red block that it goes to is
the point to which you would clamp the positive lead of a jumper cable
if you were to jump it from another vehicle. BTW - that is the point
from thru *all* power from the positive terminal of you battery gets to
the rest of the vehicle (with the exception of the hot wire to the
alternator). Notice there are three cables on that junction - one from
the battery (the positive lead), one that is the hot wire to the
starter, and the third is power to *everything* else. That third wire
goes to that fusible link that Joe P. mentioned, again - it's red, and
it is the positive power supply.

And - BTW - I do see a "Plus" sign ("+") in your third photo (partially
hidden) at the tip of the battery clamp bolt. So at least the pretty
red felt donut is on the right post (Again - red for positive).
Unfortunately the electrons don't pay attention to color.

Your hope is that the reverse-voltage protection designed into your
electronics was robust enough to protect them until the fusible link had
time to open. If you come out unscathed in the electronics, count your
blessings. If not, get familiar with www.car-part.com - it will save
you lots of money.

Stick to computers (your day for sarcasm) - except be aware that UPS
batteries use the same wire color convention: Black is neg., red is pos.
Also - inside the computer, on your power connectors, black is ground,
other voltages are colors - one of which is red.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

Bill Putney wrote:

> ...BTW - that is the point
> from thru *all* power from the positive terminal of you battery gets to
> the rest of the vehicle (with the exception of the hot wire to the
> alternator)...

Oops - Should have read "BTW - that is the point thru which *all* power
from the positive terminal of you battery gets to the rest of the
vehicle (with the exception of the hot wire to the alternator)."

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

"Mike Y" > wrote in message ...
>
> "Henry Bemis" > wrote in message
> t...
>> Hee hee! I did this once (and only once!). It was on my 56 Chevy. Dang
> thing
>> started up and the only clue it was backwards was the 8 track chewed the
> sh*t
>> out of my Arlo Guthrie tape from Columbia House!
>>
>
> Years ago I had a 1950 Willy's. Now, I didn't do it, but someone I know
> said they actually had their Willys try to turn over backwards when things
> got reversed. Allegedly there was no damage.
>

Nobody has mentioned this, and it would have been helpful to the OP, to
mention the one thing that does actually short out when you apply voltage
backwards. It's diodes that do that. From all the ignorant comments about
this costing "thousands" to fix "everything" it appears nobody actually
thought about that, or maybe as a group we're too dumb to bring it up. That
current flow went through the alternator diodes. The actual voltage was
applied everywhere, but 12 volts the wrong way isn't going to hurt anything.
It's too wimpy.

So before alternators were put on cars, they didn't have any diodes in them.
You could take a postive ground vehicle and convert it over to negative
ground with no big deal. The generators had permanent magnets in them, so
you'd have to rewire that to get it to work at full output, but again, that
was no big deal. A motor with no permanent magnets will work either way,
and obviously all the lights and other resistance loads like that don't
care.

Bill Putney wrote:
> afx wrote:
>> On Jul 14, 6:12 pm, Bill Putney > wrote:
>>
>>> afx wrote:
>>>
>>>> ...the negative cable connected to the left
>>>> side of that red post that the positive connects to the other side, is
>>>> that correctly done?...
>>>
>>> Negative = black; positive = red (the opposite of the convention used in
>>> economics).
>>>
>>> Bill Putney
>>> (To reply by e-mail, replace the last letter of the alphabet in my
>>> address with the letter 'x')
>>
>>
>> here are the pics.
>>
>>
>> http://s208.photobucket.com/albums/b...=IMAGE_006.jpg
>>
>> pic of the cables in general including the thick black one I replaced
>> that I connected to negative.
>>
>> http://s208.photobucket.com/albums/b...=IMAGE_007.jpg
>>
>> Auxiliary cable that got severed
>>
>> http://s208.photobucket.com/albums/b...=IMAGE_008.jpg
>>
>> Picture of the positive battery terminal on the positive side of the
>> battery.
>>
>>
>> Hope this helps!
>
> Heck - I might as well pile on with everybody else.
>
> The big cable in your first photo that you connected to the negative
> terminal - that is your positive lead. The red block that it goes to is
> the point to which you would clamp the positive lead of a jumper cable
> if you were to jump it from another vehicle. BTW - that is the point
> from thru *all* power from the positive terminal of you battery gets to
> the rest of the vehicle (with the exception of the hot wire to the
> alternator). Notice there are three cables on that junction - one from
> the battery (the positive lead), one that is the hot wire to the
> starter, and the third is power to *everything* else. That third wire
> goes to that fusible link that Joe P. mentioned, again - it's red, and
> it is the positive power supply.
>
> And - BTW - I do see a "Plus" sign ("+") in your third photo (partially
> hidden) at the tip of the battery clamp bolt. So at least the pretty
> red felt donut is on the right post (Again - red for positive).
> Unfortunately the electrons don't pay attention to color.
>
> Your hope is that the reverse-voltage protection designed into your
> electronics was robust enough to protect them until the fusible link had
> time to open. If you come out unscathed in the electronics, count your
> blessings. If not, get familiar with www.car-part.com - it will save
> you lots of money.
>
> Stick to computers (your day for sarcasm) - except be aware that UPS
> batteries use the same wire color convention: Black is neg., red is pos.
> Also - inside the computer, on your power connectors, black is ground,
> other voltages are colors - one of which is red.

Hi Bill...

Arghhh, now that UPS's are in play, it's probably worth mentioning to
the OP (who confesses to being a newbie) that the AC supply to the
UPS throws another twist into it, with the black being the "dangerous"
one.

It's a plot.

Take care.

Ken

Very true. Diodes don't like reversed voltage. A co-worker put the battery in
backwards on a ThermoKing refrigeration trailer, loaded of course......Guess who
got to fix his screw up? Yep, me.

That unit never did work right after that, even after replacing nearly $1,000 in
parts. So, yeah, depending on what you do it to, it can be expensive. Sometimes
though not always in parts, but the time (also expensive) to find what else got
fried.

> The actual voltage was applied everywhere, but 12 volts the wrong way isn't
> going to hurt anything. It's too wimpy.

12 volts wimpy? Here's an experiment.....lay your sweaty arm across the leads of
a 12 volt automotive battery. Please report back. When there 700 amps available
at 12 volts, somethings gonna give.

> You could take a postive ground vehicle and convert it over to negative ground
> with no big deal. The generators had permanent magnets in them, so you'd have
> to rewire that to get it to work at full output, but again, that was no big
> deal. A motor with no permanent magnets will work either way, and obviously
> all the lights and other resistance loads like that don't care.

That's the point we're making. Duh! ;-) (humor mode here).

There were even older cars that had positive to earth voltage setups, if I
recall. I'd ask my Uncle Bob, but he died long ago.

>
>Nobody has mentioned this, and it would have been helpful to the OP, to
>mention the one thing that does actually short out when you apply voltage
>backwards. It's diodes that do that. From all the ignorant comments about
>this costing "thousands" to fix "everything" it appears nobody actually
>thought about that, or maybe as a group we're too dumb to bring it up. That
>current flow went through the alternator diodes. The actual voltage was
>applied everywhere, but 12 volts the wrong way isn't going to hurt anything.
>It's too wimpy.

You are quite incorrect on that assumption. Reversed 12v will easily
take out the main control module, transmission control module, body
control module, stereo and anything else electronic in the car. I
hope that he was lucky and didn't cook anything. I have seen several
show up at the junk yard that were hooked up backwards and the cost to
repair was so high that the cars were junked.


Steve B.