Too easy. If your (metal) wrench were to slip and short the + terminal to
the body of the vehicle, you'd have a mighty big problem on your hands. On
the other hand, if the wrench were to slip while disconnecting the -
terminal, then no harm since the - terminal is wired to the chassis
anyway. Once the - terminal is disconnected then mistakes made on any +
wires or bits can't cause any trouble as there is no return to the battery.

--
Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
KG6RCR

On 8/4/2008 5:02 PM Jere Hawn wrote:

> Greetings All
>
>
>
> Here is my stupid question:
>
>
>
> The manuals (all the auto manual that I have seen in my life) say to
> disconnect the negative terminal from the batter before performing.. X, Y,
> Z,. etc.  Why the negative and not the positive one?  Does it matter, is
> negative more dangerous that the +?
>
>
>
> TIA
>
>
>
> Jere
>