90Q charging system issues - three control lights faintly on

[John Larson]

On 11:59 AM, radek at istar.ca wrote:
> Tried to drive my son's car this morning and voilà:  three idiot 
> lights light up very slightly when the car is started:  charging, 
> handbrake and brake pad usage (looks like two drum brake pads with an 
> exclamation sign in the middle, I didn't know 90Q had a provision for 
> brake pad usage light).  Voltage on centre console showing below 12V.
>
> Where to start:  instrument cluster, the trunk (no reverse light and 
> no plate light, wires must be broken)?  I wonder if a short somewhere 
> would prevent the alternator from charging fully, in other words, 
> would the drain take all of alternator's power?
>
> Car got a brand new alternator a year ago.
> TIA.
> Radek.
>
>
I see some issues here that havent been addressed.  One:  An alternator 
is a "battery maintainer", not  "battery charger".  We call people who 
rely on the alternator to charge their battery "alternator buyers".  2: 
Directly related to the first point, driving the car for a while, that 
while being less than an hour, generally pust enough charge in the 
battery for maybe a start or two, "IF" the alternator and regulator, as 
well as the wiring, are in top condition.  24 hours might do it.  3: The 
FIRST thing I would check, after the battery is FULLY charged by using a 
real battery charger for several hours, is battery condition.  You 
probably don't have the equipment to do this, but Sears does, and 
they'll do ifor free with a better than 50/50 chance of getting it 
right.  The next thing I would do is a draw test, key out, ammeter stuck 
between the negative cable and the negative post of the battery.  If 
there's a draw of more than 20-30 ma, look for it.  Last, but not least, 
I'd look at the alternator/regulator.  Output first, then pull the 
regulator and look at the brushes.  Poor output and good brushes, yank 
the alternator and have it tested.  If it's bad, buy a Genuine Bosch 
remanufactured alternator.  Sure they cost more, but buying one of those 
2 dollar FLAPS units is a dead nuts guarantee you'll become an expert at 
alternator R&R, jump starts, and get to be on a first name basis with 
the AAA tow truck driver.

John