Quick Question about Negative Battery Cable. . .

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Mar 20, 2007 | 05:33 AM

#11

markwb

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From: Groton, CT _NEBF 05, 06, 07_

Quote:

Originally Posted by J Wikoff

I once didn't unhook the negative when pulling my alternator. The power lead hit the body of the alt, which rubbed the accessory bracket as I lifted it, sparks flew, ring terminal arc welded to the body of the alt, insulation on power lead was cooked and smoking.

So I ALWAYS unhook the negative.

It sounds as if you didn't have either positive or negative disconnected if you had sparks flying.

Mar 20, 2007 | 08:00 AM

#12

Chinski

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I have done the same thing as J Wikoff. I got so used to changing the alt on my Lumina all the time that I flat out forgot to take off the neg cabe once. The sparks let you know you forgot!

Mar 20, 2007 | 08:09 AM

#13

toastedoats

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From: Fitchburg Ma _ToastedRice_

Quote:

Originally Posted by markwb

Quote:

Originally Posted by J Wikoff

It sounds as if you didn't have either positive or negative disconnected if you had sparks flying.

i believe thats what he meant...

the negative is the preferred to be unhooked because you have a MUCH lesser risk of shorting out while unhooking it... If your taking off positive while the negative is connected, it is very easy to swing your wrench into ANYTHING metal and cause a short

Mar 20, 2007 | 08:13 AM

#14

BillBoost37

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From: Enfield, CT

BillBoost37 is a glorious beacon of light

Hence the reason why GM installed an out of place looking piece of plastic on the radiator support right in line with the battery terminals on the 92-99'*.

Mar 20, 2007 | 09:03 AM

#15

skregal

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From: Missouri

I didn't unhook the battery cables when I changed a starter on a Cutlass once. I was a teenager and just forgot. Caught the car on fire. That was fun!! I'll spare you the details. Lessons learned.

Mar 20, 2007 | 10:40 AM

#16

BLACK94SSEi

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From: Melrose

Quote:

Originally Posted by toastedoats

Quote:

Originally Posted by willwren

Unhook both. The charge lead at the alternator is hot off the positive terminal from the battery.

but if you disconnect the negative; that hot lead isnt so hot under the hood, the nearest discharge location is under the seat

and for the record, it takes about 4 seconds to remove the back seat, and 10 seconds to put it back in.

X2

When I did my LIM ect, I had to remove the alternator. The negative cable was removed and nothing arked or grounded out, even when boosty touched the alt wire to the car. so im willing to bet, you will be safe just removing the negative cable.

Mar 20, 2007 | 10:53 AM

#17

J Wikoff

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Just negative removed is all you need. There is no way for the battery to make any current or voltage if there is no connection between terminals.

Mar 21, 2007 | 05:38 AM

#18

markwb

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From: Groton, CT _NEBF 05, 06, 07_

Quote:

Originally Posted by toastedoats

the negative is the preferred to be unhooked because you have a MUCH lesser risk of shorting out while unhooking it... If your taking off positive while the negative is connected, it is very easy to swing your wrench into ANYTHING metal and cause a short

Yes, I can't dispute that. I'm old school, I've always used wrenches wrapped in electrical tape or insulated when working batteries. I'm holding the line on the positive disconnect. From a technical standpoint it makes no difference.