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Car Battery

I own a 1966 Ford Mustang V-8. I was attempting to change the battery. The positive terminal was in place but when I put on the negative, smoke started coming out. After the smoke cleared, I found wiring leading to the alternator that was melted. Did I not connect it properly or is it the battery?

You probably hooked the battery up backwards but there is a exception and I got burned by it,heres how. Customer had car towed in latter brought battery, I hooked up battery correctly, burned up fuseabile link,what gives I thought.

Customer explains he had just charged battery,it was totally flat from start. Customer charged battery (from 120V AC charger) backwards so postive was no longer postive and negative was no longer negative. Repaired link,new battery all was well.

I’ve heard of the reverse polarity thing. However, the battery I installed is brand new. I’m wondering if I should take it back

It could be a short in the alternator. Have you checked for that yet?

It sounds to me that the battery was connected in reverse somehow. I think the damage happened due to a blocking diode in the alternator that is normally reversed biased. If the battery was connected somehow in reverse the diode would then be forward biased and all kinds of current would flow. There should have been a fuse in the line though to stop that kind of damage.

That was a real got ya you had with the battery.

1966? Were they still using positive ground systems then? Maybe the battery was hooked up backwards (positive ground lead to the negative terminal, and vice-versa)?

No. Ford and Chrysler went to 12 volt negative ground systems in 1956. 1955 was the last year that some U.S. cars had positive ground 6 volt systems. As far back as I can remember, the GM cars were negative ground, although the 12 volt system began being phased in in 1953 on the Oldsmobiles, senior Buicks and Cadillacs. By 1955 all GM cars were 12 volt negative ground and by 1956 all U.S. cars were 12 volt negative ground.

Man! What a memory!

Thanks for everyone’s response. I did install it backwards. Somehow the “red” cable, which I assumed was positive, is actually the negative and the “black” cable is the positive. I spoke with another Mustang owner and his cables are both “black”. Go figure…

Thanks for the compliment, but I’m just an old geezer who grew up with these cars. In fact, I still think of a new car as a car made after World War II.