Do I need a new alternator

Sun Apr 25 21:48:24 EDT 2004


I had a very similar episode on my 200 20v a few months ago after trying to remove my voltage regulator for inspection of brush length.  Of course, I was doing this at a friends house without the proper tools and was unable to totally remove the voltage regulator.  I did back out one screw and that was enough to interrupt its job (failed ground contact after retightening the screw).  I started the car... 12 volts.  The drive was from Redmond to Green Lake (fellow King countian) and by the time I pulled in the garage it was about 10 volts.  Knowing I was home safe, I then decided to see if it were the charging system and turned everything on that I could (AC, stereo, brights, etc.) and sure enough, the warning went off.  As I said before, just backing out that one screw and not getting it tight enough was enough to disrupt the charging.  

Anyway, I like the "replace the cheapest thing first" logic with the Audi.  I found a new voltage regulator at Auto Sport down by SeaTac aiport.  It was $19 total.  (206) 878-5230.  Replaced the regulator without having to remove the alternator and has worked great ever since.  

I first fiddled with the regulator in response to fluttering headlights at rid of that too. 

I found that in order to replace the voltage regulator without removal of the alternator, you need one of those 90 degree angle screwdrivers.  I got one at True Value for about $5.  It has been handy since.

Seeing how you have a rebuild that is relatively new, I would at least presume that its internals have been inspected and are in good working order.  That being the case, it is probably a wear item like the brushes or regulator.    

Hope that helps. 


  ----- Original Message ----- 
  From: davidpriebe at 
  To: 200q20v at 
  Sent: Friday, April 23, 2004 10:23 PM
  Subject: Do I need a new alternator

  I need some help diagnosing what is wrong with my charging 
  system. On Friday, driving home from work, and sitting in 
  traffic, I casually scan the gauges, and notice that the 
  voltmeter is reading just barely below 12. I haven't seen 
  it ever read this low, so I turned off all of the 
  accessories, AC and radio, and wait for the radiator fan 
  to cycle off. Typically I see a little bump up when 
  everything is off. But this time there was no bump at all. 
  Normally it reads well north of 12 volts. So for the rest 
  of my trip home I keep a close watch on the gauge, and see 
  it slowly decreasing to about 9 to 10 volts. When I got 
  home I checked the belt tension and saw that I could turn 
  it over 180 degrees, a bit loose. So today I went ahead I 
  tightened it back up. But no changes in the gauge reading, 
  still below. So now I'm thinking that there must be 
  something wrong with my alternator. The current alternator 
  was put in about 18 months ago, a rebuilt. The battery was 
  replaced about 6 months ago. So do I need a new 
  alternator, or is there someother problem? If I do need a 
  new one, any recommendations for a supplier?
  David Priebe
  Carnation, WA
  91 200tqa 182k (his)
  95.5 S6 114k (hers)
  66 MGB 41k
  200q20v mailing list
  200q20v at

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