Re. Electrical gremlins again

[Ben Swann]

I still need to hyperlink this FAQ, but if you page down, you may get some clues under
No Start, and Wiring and Electrical Problems.

http://www.gtquattro.com/FAQ.html

Because the problem seems to be more than just the starter, I'd begin under the back
seat and cleanup the battery and ground connections.  

Ben

[Date: Tue, 25 May 2010 20:47:11 -0400
From: "Radek" <radek at istar.ca>
Subject: Electrical gremlins again
To: <quattro at audifans.com>
Message-ID: <3EAF600310864E0AAE8838B24A17B6DF at Compaq>
Content-Type: text/plain;	charset="iso-8859-1"

Hi Guys;

My son's 1988 90Q is acting up again.  I took it to work this morning, stopped at a gas
station, filled up, tried to start it. It would crank but not catch.  I turned the key
back, then to "on" again and all instrument lights started flickering, then died
completely.  I turned the key back again, then back to "on" and everything was back to
normal.  Tried to start it but the starter would just click once and not turn.  Another
try - everything dead.  This went on a few times so I figured out a busted ignition
switch.  Got the car push started when the switch was kind enough to provide a good
connection and eventually got the car home - voltmeter would show a bit low, 13V while
underway.

Back at home I changed the ignition switch to a brand new one (had a spare one he
shelf).  The old switch had the typical broken plastic collar, so I thought I was OK.
NO, NO.  The flickering was gone, but starter would not crank.  When turning the key to
"start", voltage at the battery would drop to 6V.  OK, in addition to a broken ignition
switch the car may have had a shorted battery.  

I put in a new battery (had a spare one on the shelf), fully charged, and tried again.
Key turned to "on" - everything seemed fine.  To "start" - cranking, and finally the
engine runs.  I look at the voltmeter and THE ALTERNATOR IS NOT CHARGING.!  WTF?  It was
charging before, with the shorted battery and a broken ignition switch!  Voltage at
battery with engine running was showing 12V.

I put in a spare voltage regulator (had a spare one on the shelf) and it still isn't
charging!

Where to look next?  

Radek, Ottawa]