On Fri, 02 Nov 2012 08:37:42 -0500, dpb wrote:

On 11/1/2012 8:49 PM, Michael A. Terrell wrote:

wrote:

After about the third alternater in a '90 Lumina APV mu mechanic
laid down the law -" When the reading lights get left on and the
battery is dead, charge it up enough to get it here and let it sit
on the big charger for an hour". It seems that after about 1985
factory alternators are only capable of maintaining the battery,
not charging it from flat.


Not like the old 83A model on my stepvan. They cut weight every
place they can to try to meet the gas mileage requirements.

I don't really think that's it--I just went and looked at replacement
alternators listed for Chevy Lumina -- of 10 or so the amp ratings
ranged from one at 85 to 140 w/ the bulk at 100-105A. I've never had
any problem in any vehicle of recharging a _good_ battery from
discharged condition as long as there wasn't something else wrong (like
a bad regulator, etc.)

Any one vehicle may be built w/ the lower amp-output, of course, but
these days w/ the advent of A/C and all the other electrical accessories
as standard equipment more often than not the alternator is far larger
than on vehicles of yore (say '60s/early '70s and earlier, particularly).
Those 100 to 140 amp units are only good for that kind of output for
a VERY short time - untill they get hot, and die.