<VV> What *could* be damaged by reversing the battery?

[Tony Underwood]

At 01:41 hours 08/23/2005, LonzoVair at aol.com wrote:
>Hey guys,
>I just found a nice Corvair, but the idiot owner has installed the battery
>positive ground... what could possibly be broken/burnt up?


Alternator, radio (if they left it hooked up long enough to kill the 
alt diodes and then turned on the ignition and radio) and maybe a 
fuseable link if the alt held on for dear life and refused to cook 
off.    Usually something bad happens which causes either the BAT 
wire to melt or the owner witnesses the error of his ways and pulls 
the battery cable off.


>It's a 110hp with a Pertronix....

...which may or may not have fried...  same reason as above.   If so, 
only the "brain box" is likely to suffer and even then it's not 
certain that it suffered any damage at all.


>I need to know what I need to bring with me to fix it and drive it off once
>the paperwork is transferred into my name... I know I'll need to replace the
>fusable link to the horrid plastic thingy... maybe the pertronix, I 
>don't know...
>Any clues?

You shouldn't need to deal with the HLPT, which isn't inline with 
anything that could cause a huge current drain from a 
backwards-installed battery.    Again, if the cars electrical system 
was intact, the battery wouldn't have remained hooked up backwards 
for long; sparks, smoke, pops and cracks would result and the owner 
would have yanked the cable  back off if he had a lick of sense at 
all.   Even if he did not, I'd expect that the worst that would 
happen would be the alt burning up, and possibly the alt BAT wire 
would burn the insulation off, fuse into a solid wire, and then 
either burn in half or rapidly discharge the battery to nothing, 
depending on how good the battery was.   Either way, some fireworks 
and sound effects would have resulted which should have prompted ANY 
normal person to cease and desist.

...I know a nimrod who did this once, made a mess of his alternator 
and cooked the BAT wire into a gooy rod before the battery terminal 
burned the frayed end of the BAT wire off.   This cars ignition 
hadn't been turned on, so nothing else suffered any woes.

I'd take a 2 foot length of heavy wire to replace (if necessary) the 
alt to BAT wire (which may or may not be burned).   I'd take a 
battery and a standard tool kit.  Take an alternator with you if you 
feel unfortunate.

I'd first hook up the battery cables *correctly* to the battery with 
the ignition switch OFF and see if anything sparked or smoked etc.

If you get a spark/pop, unhook the alt to BAT wire and see if the 
spark/pop is still there when you put the battery terminals back on 
again.   If it's gone, you can bet the alternator is too.   After 
that, you can start checking other things like the radio 
etc.     I've seen older Delco AM radios actually survive reverse 
polarity situations with no ill effects but this is no guarantee.

However:

With any luck at all, you'll get off with just a bad alternator or 
maybe with nothing at all, and with a good battery the car might just 
start up and run.




>Thanks guys... oh, it was only $500... and I have a receipt from him
>already...


Welcome to the relatively small but prestigious list of '69 Vair 
owners.   :)


tony..