[geeks] car question

[Tyler Hardison]

On 3/11/02 12:33 PM, "Fogg, James" <JFogg at vicinity.com> wrote:

> Much too weird.
> 
> I wouldn't run it until you check something. Start the engine and take a
> voltmeter and see if the polarity of the system is correct (red wire to a
> live fuse in the block, black wire to chassis, if the meter swings backwards
> you're in trouble.
> 
> This is so weird that it causes one to search the outer limits of
> possiblities...
> 
> I am probably way off base here, but in the old DC generators used in autos
> (like 1960 and before), you could loose the core magnetism and you would
> have to flash the fields with a little juice to introduce a moment of
> magnetism and then the generator would self-excite (not to be confused with
> masturbation). If you did it wrong, the generator could reverse polarity. I
> didn't think this was an issue with modern cars, but maybe.....
> 
> Unless the battery was stone cold dead and you reversed polarity on the
> battery when you jumped it? If that was the case the battery would have
> gotten warm when you ran the engine. It also means the starter would have
> turned the engine backwards. A modern engine shouldn't run backwards (but a
> diesel engine can run poorly in reverse, depending on design).
> 

Yeah I just saw this. I'm voting on reversed battery polarity.. Some modern
cars have a "non-reversible" starter.. Meaning that regardless of applied
current it only spins one direction.

Cheers

Tyler.