90Q charging system issues - three control lights faintly on - RESOLVED

[radek at istar.ca]

Thanks for all your input guys.  For the record:  the culprit was the  
voltage regulator, with one of the brushes having disconnected (one of  
the brushes fell off, together with a spring, when I took the VR out.   
The other one stayed in place).  Replacing with a new old VR resolved  
the problem.

I was very surprised to see, though, that the brushes were nearly  
completely worn out after only a year of use.  Last June, I purchased  
a brand new, Mexican-made, alternator.  Also cleaned all connections  
and added additional ground wires.   The VR was Bosch.  I've never  
seen brushes wear out so quickly.

When I have a bit more time, I will stick the old broken VR back in  
the alternator and go see what Canadian Tire warranty is worth (the  
thing came with a 3-yr warranty).
Thanks again!

Radek.



> Message: 1
> Date: Sun, 22 May 2011 13:47:19 -0700
> From: John Larson <john at westcoastgarage.net>
> To: radek at istar.ca
> Cc: quattro at audifans.com
> Subject: Re: 90Q charging system issues - three control lights faintly
         on
Message-ID: <4DD97657.8030001 at westcoastgarage.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

On 11:59 AM, radek at istar.ca wrote:


[Show Quoted Text - 17 lines][Hide Quoted Text]
Tried to drive my son's car this morning and voil?:  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