Re: Battery undercharged

[Albert Ng <alng@purdue.edu>]

Hi All,


While we are on the topic of the Auid's charging system. I would like to 
ask a simple question which about the alternator on my '87 5kcst. After 
a couple of months of observation, I found that my one year old 
remanufactured alternator started making some noise when under load; 
such as the rad. fan kicks in; whenever the load increase; such as everything
are turn on with the rad. fan kicks in, the noise will become more 
obvious, but after I turn off all the things(not the engine) and the rad. 
fan stops, the noise disappear.


Is that means my alternator going south again? or It's just normal?


TIA


Albert Ng
'87 5kcst

On Fri, 6 Dec 1996, Graydon D. Stuckey wrote:

> On Fri, 6 Dec 1996 STEADIRIC@aol.com wrote:
> 
> > >weeks.  I
> > >had the battery checked and the verdict was the battery was okay, but
> > >undercharged; I should have my charging system checked, or drive more.
> > 
> > I hear you on this one and was thinking of trying the kit to see if it 
> > helped.. I also found that by doing a "Maintence" charge on the battery 
> > once or twice a month I don't have the problem.......
> 
> Guys,
> 
> 	I don't think this should be necessary even on the 5000CSTQ with 
> all its toys.  I had to get a new battery and a rebuilt alternator, but 
> after that, my entire system ran fine.  In the course of the 
> troubleshooting, I checked current draw in every circuit in the fuse box, 
> both under normal operating conditions, and with the car off.  There are 
> very few really high draw circuits on the 5000, and the current when off 
> was less than 25 milliamps which is right in the ballpark for most luxury 
> cars.  Interestingly, the display on my radio drew almost half of that 25mA.
> 
> 	Now, I admit, the 90 amp alternator doesn't produce 90 amps until 
> you have it revved up a bit, but if you put a voltmeter on the alternator 
> output instead of looking at the HVAC display, you'll find that even under 
> high load, with the blower, lights, seat heaters, and the rear defroster 
> running, teh voltage only drops to 13.5 at the lowest.  As long as you're 
> staying above 12.7 volts, you are still charging the battery, and not 
> drawing from it.
> 
> Later, ---------------------------------------------------------- 
> Graydon D. Stuckey 	'85 Mazda RX7 GS, no toys 
> graydon@apollo.gmi.edu 	'86 Audi 5000 CS Turbo Quattro, has toys
> Flint, Michigan USA	'89 Thunderbird SC, lotsa toys
> 
> 
>