[no subject]

["David Swingle" <dswingle@xxxx>]

I've got to jump in on this one. I can't understand what electrical 
engineering principle could possibly impact the requirement to 
connect the positive or the negative first, with respect to inrush 
surges as the connection is made. It's a single circuit. Current flow 
and resulting voltage sags/surges take a complete circuit, and will 
happen whether Pos or Neg is hooked up first. The surge is completely 
a function of the voltage offered (the battery) vs the load being 
connected-to (the car's electrical system). Hooking up one side or 
the other first makes no difference, no current flows until the final 
connection is made. 

The normal reason for connecting the positive first is that is less 
likely that you will touch a hot (+) wire to ground by accident, 
since the grounds aren't hooked up yet. Using jumper cables as an 
example, if you were to connect the neg circuit first, and then 
connect one end of the pos, and accidently drop the other one on the 
car body, you'd get a short and lots of sparks. If you connect the 
positive side first, later accidentally dropping the neg to part of 
the car would have no effect other than completing the circuit. 

Dave Swingle


--- In dmcnews@xxxx, srubano@xxxx wrote:
> 
> By connecting the positive cable first THEN the negative cable, you 
> eliminate/minimize any surge that is sent into the electrical 
system 
> of BOTH cars. I have seen countless amount of times people 
installing 
> new batteries into their car and connecting the ground first then 
the 
> positive lead and then wonder why all of their bulbs all burnt out 
at 
> the same time in their dash board or why their computer fried.
> 
> Steve
>